Total Leucocytes / WBC Count (TLC) Test

A white blood count test evaluates a sample to measure the number of white blood cells in the blood. The white blood count test results help diagnose infections, diseases or other foreign substances that can cause illness.

Your blood is made of different types of cells. This includes red blood cells, white blood cells, platelets and plasma. All cells play a specific role and contribute towards keeping your body safe and healthy. White blood cells play a defensive role in your body and account for about 1% of your blood. Despite the low count, they are crucial in keeping you safe.

White blood cells can also be called your immunity cells which are constantly at war with external foreign substances that can make you sick. WBCs flow through your blood and help the body fight against bacteria, viruses and other foreign invaders that threaten your well-being.

Whenever your body recognises a threat and identifies a body part being attacked, it signals the white blood cells to rush in and destroy the foreign substances. This mechanism prevents illness and keeps you healthy.

WBCs are created in the bone marrow and stored in your blood and lymph tissues. The white blood cells are made of different cells and some cells, like the neutrophils, have a short life span. Hence, your bone marrow is constantly producing white blood cells.

The total leucocyte count test is prescribed for people who show symptoms of illness such as fever, body chills, headache, pain, infection, allergic reaction, inflammation. Your doctor may also prescribe the test if you show symptoms related to a blood disorder or auto-immune disorder.

According to the latest reports released by ICMR-National Centre for Disease Informatics and Research, Leukaemia accounts for about half of all the childhood cancers in children below the age of 14 — 46.4 per cent in boys and 44.3 per cent in girls.

Infections, Autoimmune disorders, Hereditary disorders, Leukaemia and several other medical conditions

The total leucocyte count test measures the levels of white blood cells in the body. Abnormality in the WBC count results indicates the presence of a medical condition.

The test is ordered if you experience any of these functions:

• Body aches
• Fever
• Chills
• Headaches
• Bladder infections
• Painful urine
• Lung infections
• Difficulty in coughing and breathing
• Mouth sores
• Sinus infections
• Stuffy nose
• Redness and swelling
• Pus formation
• Sore throat
• Skin rashes
• Fatigue

Some conditions for which a total white blood count test can be prescribed are:

• Viral or bacterial Infections
• Inflammation
• Leukaemia
• Auto-immune disorder
• Cancer
• Severe physical injury
• Hodgkin disease
• Tissue damage such as burns

After assessing the results of the total leukocyte count test, your doctor can order some other blood tests that will help them reach a final diagnosis. Once a definitive diagnosis is made, your doctor can request frequent white blood count tests to check the effectiveness of the treatment plan.

The total white blood count test results can vary if you are taking certain medications, such as antibiotics, anticonvulsants, cancer therapy drugs, water pills and antiallergens. Talk to your doctor about any medication you are taking and tell them about any fever or allergy symptoms you may have experienced lately.

The white blood count test is prescribed by the doctor if the patient displays signs that relate to any infection, inflammation, blood disorder or auto-immune disease. The WBC count test is also ordered as part of a routine test and is included with a complete blood count. If you are diagnosed with an infection or a disorder that causes abnormal WBC count, your doctor may ask you to repeat the test during your treatment plan.

The doctor and your diagnosed condition decide the frequency at which the test is repeated. The total leucocytes count test results will help your doctor evaluate if your treatment plan is working or not.

If your results do not improve, your treatment plan may need some tweaking. The total white blood count test may be taken every four to six hours for patients with severe medical conditions. This is mainly done if a patient's condition continues to deteriorate.

Before the Test

Usually, an total leucocytes count test doesn't need any special prep. If you're taking this test with another one, your doctor might tell you to avoid eating certain foods. It's always a good idea to talk to your doctor before the test to get the best results.

During the Test

The phlebotomist will take a blood sample from a vein in your arm. Here's what you can expect:

• The spot where they're going to insert the needle is cleaned with an antiseptic.
• A band/tourniquet will be wrapped around your arm to make your veins stand out more.
• A needle will be guided into the vein to draw the blood sample. This might take a couple of seconds, and you might feel a quick pinch.
• The sample blood will be collected in a vial/small tube with your details on it.

After the Test

After the Blood is Collected:

• A bandage will be applied over the puncture spot to stop the bleeding.
• You might develop a bruise, but feeling dizzy is rare. You might be asked to sit down for a bit.
• If you notice any bleeding, pain, or a rash at the puncture site, let your doctor know.

The total leucocyte count test measures the levels of different white blood cells present in the blood. It measures the levels of five major types of white blood cells as a total count.

Neutrophils

Neutrophils are responsible for killing and digesting foreign bacterias and fungi. They make the majority of the white blood cells and act as the first line of defence during infection. Neutrophils are quick to respond and they multiply quickly.

Lymphocytes

Lymphocytes recognise foreign invaders and also constitute the first line of defence. The lymph (clear white fluid in the body) is mainly made of lymphocytes. There are three types of lymphocytes: B cells, T cells and natural killer cells.

Eosinophils

Eosinophils identify and target parasites like worms and it influences the allergic inflammatory responses. They also help with allergic reactions and kill cancer cells.

Monocytes

These cells have a longer lifespan when compared to other white blood cells and they also help break down bacterias. Monocytes are the largest type of leukocytes and they divide into three different cells with various protective functions.

Basophils

Basophils come into play when your body undergoes an allergic reaction. They are responsible for defending the body against bacteria and parasites. Basophils release two chemicals called heparin and histamine. Both these chemicals play vital roles in maintaining normal body functions.

The total leukocyte count test does not evaluate the changes occurring at the organ level and only measures the levels of different white blood cells. Your doctor will assess your results that will help them reach a diagnosis.

A higher or lower value than the average range can be a sign of an underlying medical condition. Abnormalities in the percentage of a specific type of white blood count can also be a sign of a disorder. 

The normal values and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

A variation in the result of the white blood cell count test indicates a medical disorder. A higher or upper value can mean different things and the doctor will give a final diagnosis. A high white blood count is called leukocytosis and can indicate a number of conditions or diseases.

This includes bacterial and viral infections, rheumatoid arthritis, vasculitis, inflammatory bowel disease or inflammation. It can also be a sign of allergies, leukaemia (white blood cancer), conditions that result in tissue death such as trauma, burns, heart attack.

A low white blood count is called leukopenia and can result from conditions such as damaged bone marrow due to viral infections like Covid 19, Dengue, radiation therapy, toxins or chemotherapy. It can also indicate bone marrow disorders such as vitamin B12 or folate deficiency, cancers such as lymphoma, auto-immune diseases, dietary deficiency or sepsis. Infections of the immune system like HIV also result in lowered WBC count.

Doctors may use WBC count tests as a way to monitor medical conditions. Results of leukocyte count tests that continue to fall or rise to abnormal values indicate that the disease of the condition is not improving. WBC count that returns back to an average value suggests that the treatment is working and the situation is improving.

A TLC  test can have varying costs depending on the city and the laboratory. Typically, the price for a TLC test falls between INR 129 and INR 219. Here's a breakdown of the average charges for a TLC test in select major cities in India: