Table of Contents<\/p>\nToggle<\/span><\/path><\/svg><\/svg><\/span><\/span><\/label>Introduction<\/a><\/li>What Is a Fever?<\/a><\/li>What Are the Types of Fever?<\/a><\/li>Common Symptoms of Fever<\/a><\/li>Stages of a Fever<\/a><\/li>Diagnosis of Different Types of Fever<\/a><\/li>Tips for Managing Fever Correctly<\/a><\/li>Precautions for Fever<\/a><\/li>When to See a Doctor?<\/a><\/li>Conclusion<\/a><\/li>Frequently Asked Questions (FAQs)<\/a><\/li>References<\/a><\/li><\/ul><\/nav><\/div>\n \n <\/span>\n \n <\/a>\n<\/span>Introduction<\/strong><\/span><\/h2>\n\n\n\nFever is one of the most common signs that your body is responding to an infection or another health condition1<\/a><\/sup>. Although a rise in body temperature can feel worrying, it is often a normal part of your body\u2019s defence system and usually improves with appropriate care. In some cases, however, fever can be a sign of an illness that needs medical attention1<\/a>,2<\/a><\/sup>. In this blog, we explain what fever is the main types of fever, common symptoms, stages of fever, safe management tips, and when to consult a doctor.<\/p>\n\n\n\n<\/p>\n\n\n\n<\/span>What Is a Fever?<\/strong><\/span><\/h2>\n\n\n\nA fever is a temporary increase in body temperature. It happens when the body\u2019s temperature-control centre in the brain, called the hypothalamus, raises the body\u2019s \u201cset point\u201d in response to infection, inflammation, or other triggers2<\/a><\/sup>.<\/p>\n\n\n\nNormal body temperature is\u00a0generally around\u00a036.5\u00b0C to 37.5\u00b0C (97.7\u00b0F to 99.5\u00b0F), although it can vary slightly between individuals and throughout the\u00a0day2<\/a><\/sup>.<\/p>\n\n\n\nIn adults, a\u00a0body\u00a0temperature of 38\u00b0C (100.4\u00b0F) or higher is\u00a0generally considered\u00a0a fever. The exact reading can vary depending on where and how the temperature is measured, such as by mouth, ear, forehead, armpit, or rectum2<\/a><\/sup>.<\/p>\n\n\n\nNote:<\/strong>\u00a0Fever itself is not a disease. It is a sign\u00a0that tells you the immune system is responding to an underlying problem, most often an infection.<\/em><\/p>\n\n\n\n<\/span>What Are the Types of Fever?<\/strong><\/span><\/h2>\n\n\n\nYou may have wondered how many types of fever actually exist.<\/p>\n\n\n\nFever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\nUnderstanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n1. Types of fever based on body temperature<\/strong><\/h3>\n\n\n\nThe severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
Fever is one of the most common signs that your body is responding to an infection or another health condition1<\/a><\/sup>. Although a rise in body temperature can feel worrying, it is often a normal part of your body\u2019s defence system and usually improves with appropriate care. In some cases, however, fever can be a sign of an illness that needs medical attention1<\/a>,2<\/a><\/sup>. In this blog, we explain what fever is the main types of fever, common symptoms, stages of fever, safe management tips, and when to consult a doctor.<\/p>\n\n\n\n<\/p>\n\n\n\n<\/span>What Is a Fever?<\/strong><\/span><\/h2>\n\n\n\nA fever is a temporary increase in body temperature. It happens when the body\u2019s temperature-control centre in the brain, called the hypothalamus, raises the body\u2019s \u201cset point\u201d in response to infection, inflammation, or other triggers2<\/a><\/sup>.<\/p>\n\n\n\nNormal body temperature is\u00a0generally around\u00a036.5\u00b0C to 37.5\u00b0C (97.7\u00b0F to 99.5\u00b0F), although it can vary slightly between individuals and throughout the\u00a0day2<\/a><\/sup>.<\/p>\n\n\n\nIn adults, a\u00a0body\u00a0temperature of 38\u00b0C (100.4\u00b0F) or higher is\u00a0generally considered\u00a0a fever. The exact reading can vary depending on where and how the temperature is measured, such as by mouth, ear, forehead, armpit, or rectum2<\/a><\/sup>.<\/p>\n\n\n\nNote:<\/strong>\u00a0Fever itself is not a disease. It is a sign\u00a0that tells you the immune system is responding to an underlying problem, most often an infection.<\/em><\/p>\n\n\n\n<\/span>What Are the Types of Fever?<\/strong><\/span><\/h2>\n\n\n\nYou may have wondered how many types of fever actually exist.<\/p>\n\n\n\nFever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\nUnderstanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n1. Types of fever based on body temperature<\/strong><\/h3>\n\n\n\nThe severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
<\/p>\n\n\n\n
A fever is a temporary increase in body temperature. It happens when the body\u2019s temperature-control centre in the brain, called the hypothalamus, raises the body\u2019s \u201cset point\u201d in response to infection, inflammation, or other triggers2<\/a><\/sup>.<\/p>\n\n\n\nNormal body temperature is\u00a0generally around\u00a036.5\u00b0C to 37.5\u00b0C (97.7\u00b0F to 99.5\u00b0F), although it can vary slightly between individuals and throughout the\u00a0day2<\/a><\/sup>.<\/p>\n\n\n\nIn adults, a\u00a0body\u00a0temperature of 38\u00b0C (100.4\u00b0F) or higher is\u00a0generally considered\u00a0a fever. The exact reading can vary depending on where and how the temperature is measured, such as by mouth, ear, forehead, armpit, or rectum2<\/a><\/sup>.<\/p>\n\n\n\nNote:<\/strong>\u00a0Fever itself is not a disease. It is a sign\u00a0that tells you the immune system is responding to an underlying problem, most often an infection.<\/em><\/p>\n\n\n\n<\/span>What Are the Types of Fever?<\/strong><\/span><\/h2>\n\n\n\nYou may have wondered how many types of fever actually exist.<\/p>\n\n\n\nFever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\nUnderstanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n1. Types of fever based on body temperature<\/strong><\/h3>\n\n\n\nThe severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
Normal body temperature is\u00a0generally around\u00a036.5\u00b0C to 37.5\u00b0C (97.7\u00b0F to 99.5\u00b0F), although it can vary slightly between individuals and throughout the\u00a0day2<\/a><\/sup>.<\/p>\n\n\n\nIn adults, a\u00a0body\u00a0temperature of 38\u00b0C (100.4\u00b0F) or higher is\u00a0generally considered\u00a0a fever. The exact reading can vary depending on where and how the temperature is measured, such as by mouth, ear, forehead, armpit, or rectum2<\/a><\/sup>.<\/p>\n\n\n\nNote:<\/strong>\u00a0Fever itself is not a disease. It is a sign\u00a0that tells you the immune system is responding to an underlying problem, most often an infection.<\/em><\/p>\n\n\n\n<\/span>What Are the Types of Fever?<\/strong><\/span><\/h2>\n\n\n\nYou may have wondered how many types of fever actually exist.<\/p>\n\n\n\nFever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\nUnderstanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n1. Types of fever based on body temperature<\/strong><\/h3>\n\n\n\nThe severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
In adults, a\u00a0body\u00a0temperature of 38\u00b0C (100.4\u00b0F) or higher is\u00a0generally considered\u00a0a fever. The exact reading can vary depending on where and how the temperature is measured, such as by mouth, ear, forehead, armpit, or rectum2<\/a><\/sup>.<\/p>\n\n\n\nNote:<\/strong>\u00a0Fever itself is not a disease. It is a sign\u00a0that tells you the immune system is responding to an underlying problem, most often an infection.<\/em><\/p>\n\n\n\n<\/span>What Are the Types of Fever?<\/strong><\/span><\/h2>\n\n\n\nYou may have wondered how many types of fever actually exist.<\/p>\n\n\n\nFever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\nUnderstanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n1. Types of fever based on body temperature<\/strong><\/h3>\n\n\n\nThe severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
Note:<\/strong>\u00a0Fever itself is not a disease. It is a sign\u00a0that tells you the immune system is responding to an underlying problem, most often an infection.<\/em><\/p>\n\n\n\n<\/span>What Are the Types of Fever?<\/strong><\/span><\/h2>\n\n\n\nYou may have wondered how many types of fever actually exist.<\/p>\n\n\n\nFever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\nUnderstanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n1. Types of fever based on body temperature<\/strong><\/h3>\n\n\n\nThe severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
You may have wondered how many types of fever actually exist.<\/p>\n\n\n\n
Fever can be classified in several ways. Doctors commonly classify fever based on body temperature, how long it lasts, the pattern of temperature changes, and its underlying cause.<\/p>\n\n\n\n
Understanding the different types of fever can help you describe your symptoms more clearly to a doctor and may guide the next steps in care. Let us look at the main ways fever is classified:<\/p>\n\n\n\n
The severity of fever depends on how much the body temperature rises above the usual range2<\/a><\/sup>.<\/p>\n\n\n\nType<\/strong>\u00a0<\/td>Body Temperature<\/strong>\u00a0<\/td>Description<\/strong>\u00a0<\/td><\/tr>Low-grade fever\u00a0<\/td>37.3\u00b0C to 38.0\u00b0C (99.1\u00b0F to 100.4\u00b0F)\u00a0<\/td>A mild increase in temperature. It may occur with viral infections, mild bacterial infections, after\u00a0vaccination, or with inflammatory conditions. It usually does not\u00a0require specific\u00a0treatment unless you feel\u00a0very uncomfortable\u00a0or symptoms worsen.\u00a0<\/td><\/tr>Moderate fever\u00a0<\/td>38.1\u00b0C to 39.0\u00b0C (100.6\u00b0F to 102.2\u00b0F)\u00a0<\/td>Common in infections such as influenza, COVID-19, urinary tract infections, and pneumonia. Most people experience chills, fatigue, headache, and body aches at this stage.\u00a0<\/td><\/tr>High-grade fever\u00a0<\/td>39.1\u00b0C to 41\u00b0C (102.4\u00b0F to 105.8\u00b0F)\u00a0<\/td>May\u00a0indicate\u00a0a more serious infection or inflammatory condition. Medical attention is recommended if the fever persists or occurs with confusion, difficulty breathing, severe pain, dehydration, or worsening symptoms.\u00a0\u00a0<\/td><\/tr>Hyperpyrexia\u00a0<\/td>Above 41\u00b0C (105.8\u00b0F)\u00a0<\/td>A medical emergency that needs immediate care. Hyperpyrexia can occur with severe infections, heat stroke, certain nervous system conditions, or serious drug reactions. If not treated promptly, it\u00a0may lead to organ damage.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n2. Types of\u00a0fever\u00a0based on\u00a0duration<\/strong><\/h3>\n\n\n\nThe length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
The length of time a fever lasts can provide clues about its cause3<\/a><\/sup>.<\/p>\n\n\n\n\nAcute Fever<\/strong>\n\nLasts less than 7 days.<\/li>\n\n\n\nMost commonly caused\u00a0by viral infections like\u00a0the\u00a0common cold.<\/li>\n\n\n\nUsually\u00a0improves\u00a0once the underlying illness\u00a0gets better.<\/li>\n<\/ul>\n<\/li>\n\n\n\nSubacute Fever<\/strong>\n\nPersists for 7 to 14 days.<\/li>\n\n\n\nMay occur with infections such as typhoid fever.<\/li>\n\n\n\nFurther medical evaluation may be needed if the cause is not obvious.<\/li>\n<\/ul>\n<\/li>\n\n\n\nChronic or Persistent Fever<\/strong>\n\nLasts more than 14 days.<\/li>\n\n\n\nPossible causes\u00a0include tuberculosis, HIV,\u00a0some\u00a0cancers,\u00a0autoimmune conditions, and other long-term infections or inflammatory illnesses.<\/li>\n\n\n\nRequires thorough medical investigation to\u00a0determine\u00a0the underlying cause.<\/li>\n<\/ul>\n<\/li>\n<\/ul><\/div>Show Full Article<\/button><\/div>\n\n\n\n3. Types of\u00a0fever\u00a0based on\u00a0temperature\u00a0pattern<\/strong><\/h3>\n\n\n\nThe way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n\nContinuous (Sustained) Fever:<\/strong> In continuous fever, body temperature stays high throughout the day and changes by less than 1\u00b0C (1.8\u00b0F) over 24 hours. The temperature does not return to normal during this period. Common causes\u00a0include3<\/a><\/sup>:\n\nTyphoid fever<\/li>\n\n\n\nLobar pneumonia<\/li>\n\n\n\nUrinary tract infections<\/strong><\/a><\/li>\n<\/ul>\n<\/li>\n\n\n\nRemittent Fever:<\/strong>\u00a0In remittent fever, the temperature stays above normal but rises and falls by more than\u00a01\u00b0C during the day. It does not return to normal between these changes. Common causes\u00a0include3<\/a><\/sup>:\n\nInfective endocarditis<\/li>\n\n\n\nCertain bacterial infections, such as\u00a0brucellosis\u00a0and rickettsial infections<\/li>\n<\/ul>\n<\/li>\n\n\n\nIntermittent Fever:<\/strong>\u00a0In intermittent fever, the temperature rises for several hours, returns to normal, and then rises again later. Common causes\u00a0include3<\/a><\/sup>:\n\nMalaria<\/a><\/strong><\/li>\n\n\n\nLeptospirosis<\/a><\/strong><\/li>\n\n\n\nCertain bacterial infections, including sepsis<\/li>\n<\/ul>\n<\/li>\n\n\n\nDepending on the timing, intermittent fever may be described as:\n\nQuotidian:<\/strong>\u00a0Fever occurs every\u00a0day.<\/li>\n\n\n\nTertian:<\/strong>\u00a0Fever occurs every\u00a0alternate day, or about\u00a0every 48 hours.<\/li>\n\n\n\nQuartan:<\/strong>\u00a0Fever occurs every\u00a0third day, or about\u00a0every 72 hours.<\/li>\n<\/ul>\n<\/li>\n\n\n\nRelapsing Fever:<\/strong> Relapsing fever is characterised by episodes of fever lasting several days, followed by fever-free periods before the fever returns3<\/a><\/sup>. Common causes include:\n\nTick-borne or louse-borne relapsing fever (Borrelia infection)<\/li>\n\n\n\nCertain forms of\u00a0Malaria<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n4. Types of\u00a0fever\u00a0based on\u00a0underlying\u00a0cause<\/strong><\/h3>\n\n\n\nFever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n\nInfectious Fever:<\/strong> This is the most common type of fever. It is caused by microorganisms, or germs, such as viruses, bacteria, fungi, or parasites. Examples\u00a0include3<\/a><\/sup>:\n\nCommon cold\u00a0<\/li>\n\n\n\nInfluenza\u00a0<\/li>\n\n\n\nCOVID-19<\/li>\n\n\n\nDengue<\/a><\/strong><\/li>\n\n\n\nMalaria\u00a0<\/li>\n\n\n\nTuberculosis<\/a><\/strong><\/li>\n\n\n\nPneumonia<\/a><\/strong><\/li>\n\n\n\nUrinary tract infections\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nInflammatory or Autoimmune Fever:<\/strong>\u00a0This occurs when inflammation activates the immune system even when there is no infection. Autoimmune conditions are illnesses in which the immune system mistakenly attacks the body\u2019s own tissues. Examples\u00a0include4<\/a><\/sup>:\n\nRheumatoid arthritis\u00a0<\/li>\n\n\n\nSystemic lupus erythematosus (SLE)\u00a0<\/li>\n\n\n\nVasculitis\u00a0<\/li>\n\n\n\nAdult-onset Still\u2019s disease\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nDrug-Induced\u00a0Fever:<\/strong>\u00a0Some medications can trigger fever as an adverse reaction, even without an infection. Common medications\u00a0include5<\/a><\/sup>:\n\nCertain antibiotics\u00a0<\/li>\n\n\n\nAnticonvulsants\u00a0<\/li>\n\n\n\nAllopurinol\u00a0<\/li>\n\n\n\nHeparin\u00a0<\/li>\n\n\n\nSome chemotherapy and immunotherapy drugs\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nNeoplastic (Cancer-Related) Fever:<\/strong>\u00a0Certain cancers can cause persistent fever through inflammation or immune\u00a0system activation. Examples\u00a0include6<\/a><\/sup>:\n\nLymphoma\u00a0<\/li>\n\n\n\nLeukaemia\u00a0<\/li>\n\n\n\nRenal cell carcinoma\u00a0<\/li>\n\n\n\nOther advanced cancers\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nHeat-Related Fever (Hyperthermia):<\/strong>\u00a0Hyperthermia is different from true fever. In fever, the brain raises the body\u2019s temperature set point. In hyperthermia, the body overheats because it cannot lose enough heat. Examples\u00a0include2<\/a>,7<\/a><\/sup>:\n\nHeat stroke\u00a0<\/li>\n\n\n\nHeat exhaustion\u00a0<\/li>\n\n\n\nExcessive environmental heat exposure\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\nFever of Unknown Origin:<\/strong>\u00a0Fever of unknown origin refers to a persistent fever, usually 38.3\u00b0C (101\u00b0F) or higher on\u00a0multiple\u00a0occasions, that\u00a0remains\u00a0unexplained after\u00a0appropriate medical\u00a0evaluation. Common causes\u00a0include8<\/a><\/sup>:\n\nUndiagnosed\u00a0infections<\/li>\n\n\n\nAutoimmune diseases<\/li>\n\n\n\nCancers\u00a0(malignancies)<\/li>\n\n\n\nRare inflammatory disorders<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<\/span>Common Symptoms of Fever<\/strong><\/span><\/h2>\n\n\n\n<\/figure><\/div>\n\n\nFever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
The way body temperature changes throughout the day often provides important diagnostic clues.<\/p>\n\n\n\n
Fever can be classified based on what\u00a0is\u00a0causing it:\u00a0<\/p>\n\n\n\n
Fever symptoms can vary depending on the cause, how high the temperature is, and a person\u2019s age. While a raised body temperature is the main sign of fever, other symptoms may\u00a0indicate\u00a0that the body is fighting an infection or illness. These\u00a0include9<\/a>,10<\/a><\/sup>:<\/p>\n\n\n\n\nElevated body temperature\u00a0<\/li>\n\n\n\nChills<\/li>\n\n\n\nFatigue<\/li>\n\n\n\nWeakness<\/li>\n\n\n\nShivering<\/li>\n\n\n\nSweating<\/li>\n\n\n\nHeadache<\/a><\/strong><\/li>\n\n\n\nMuscle aches\u00a0(Myalgia)<\/li>\n\n\n\nJoint pain\u00a0(Arthralgia)<\/a><\/strong>\u00a0<\/li>\n\n\n\nFlushed or warm skin\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Stages of a Fever<\/strong><\/span><\/h2>\n\n\n\nFever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
Fever often progresses through three stages as the body raises,\u00a0maintains, and then lowers its temperature in response to an infection or another trigger. These\u00a0include2<\/a>,11<\/a><\/sup>:<\/p>\n\n\n\n\nChill\u00a0stage (onset\u00a0stage):<\/strong>\u00a0The hypothalamus raises the body\u2019s temperature set point. To reach this higher temperature, the body\u00a0produces\u00a0and\u00a0conserves\u00a0heat. This is why you may feel cold, shiver, or want to cover yourself even though your temperature is rising.\u00a0<\/li>\n\n\n\nPlateau\u00a0stage (hot\u00a0stage):<\/strong>\u00a0The body reaches the new temperature set point and keeps the temperature elevated while the immune system responds to the underlying cause. During this stage, you may feel hot, tired, or achy.\u00a0<\/li>\n\n\n\nDefervescence (recovery or\u00a0sweating\u00a0stage):<\/strong> As the illness improves or treatment begins to work, the hypothalamus lowers the temperature set point. The body then releases extra heat, often through sweating. This is sometimes called the recovery stage.\u00a0<\/li>\n<\/ul>\n\n\n\n<\/span>Diagnosis of Different Types of Fever<\/strong><\/span><\/h2>\n\n\n\nDiagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
Diagnosing a fever means measuring body temperature and finding the underlying cause. Depending on your symptoms and medical history, your doctor may recommend one or more of the following tests or checks2<\/a>,8<\/a><\/sup>:<\/p>\n\n\n\n\nMedical history:<\/strong>\u00a0Your doctor may ask how long\u00a0the\u00a0fever has lasted, whether it comes\u00a0and\u00a0goes, and whether you have\u00a0symptoms\u00a0such as cough, pain, rash,\u00a0travel\u00a0history, exposure to infections,\u00a0recent medicines, or\u00a0existing\u00a0health\u00a0conditions.<\/li>\n\n\n\nPhysical examination:<\/strong>\u00a0To look for signs of infection or inflammation by checking vital signs, throat, ears, lungs, skin, abdomen, and lymph nodes.<\/li>\n\n\n\nBlood tests<\/a>:<\/strong>\u00a0Tests such\u00a0as\u00a0a\u00a0complete blood count<\/a><\/strong>, blood culture, C-reactive protein<\/a><\/strong>, erythrocyte sedimentation rate, procalcitonin, and liver and kidney function tests\u00a0may help detect infection, inflammation, or organ involvement.<\/li>\n\n\n\nUrine, stool, or respiratory tests:<\/strong>\u00a0These may include\u00a0urinalysis, urine culture, stool examination\u00a0or\u00a0culture, throat swab, and sputum culture to\u00a0look for\u00a0infections in specific\u00a0parts of the\u00a0body.<\/li>\n\n\n\nDisease-specific tests:\u00a0<\/strong>Such as malaria tests<\/a><\/strong>, dengue NS1 antigen<\/a><\/strong> or antibody tests, typhoid blood culture, COVID-19 and influenza tests, tuberculosis tests<\/a><\/strong>, and other region-specific infectious disease tests when clinically indicated.<\/li>\n\n\n\nImaging studies:<\/strong>\u00a0Including chest X-ray, CT scan, or MRI to identify infections or inflammation affecting internal organs.<\/li>\n\n\n\nSpecial investigations:<\/strong>\u00a0For persistent, recurrent, or unexplained fever, tests such\u00a0as autoimmune markers, HIV testing, bone marrow examination, biopsy, or PET-CT scan\u00a0may be considered.<\/li>\n<\/ul>\n\n\n\n<\/span>Tips for Managing Fever Correctly<\/strong><\/span><\/h2>\n\n\n\nMost fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery
Most fevers caused by mild viral infections improve with supportive care. These steps can help reduce discomfort and support recovery