Lump Under Armpit: Causes, Symptoms, Home Remedies & More 

Introduction

Noticing a lump under the armpit can be unsettling and often makes you anxious. It is extremely normal to get worried when you notice something like this in such sensitive areas. But an important thing is that not all lumps under the armpit are dangerous; many are harmless and may result from minor infections, use of certain medications or vaccines or may be a benign cyst¹. Still, it is important to consult your doctor for confirmation. 

This article is a guide which might help you understand what the armpit lumps actually are, how they are caused, their symptoms and diagnostic procedures, and the treatment methods followed. It will also discuss some simple home-based approaches for minor cases. So, let’s go ahead! 

What Are Armpit Lumps?

Armpit lumps are any bumps or swelling felt under the armpit. They can be present under the skin of your armpit or deep inside. These lumps can be soft or hard, moving or fixed at a position, and painless or painful. They can occur along with several other symptoms. A common reason behind armpit lumps is the swelling of lymph nodes in this region².

These lumps in most cases are harmless, whereas sometimes they may also indicate underlying conditions which need medical attention^1,2. Understanding their nature is the first step in knowing when to monitor them and when to seek medical advice. 

Causes of Armpit Lumps

Armpits can develop lumps for various reasons. The following describes the most common armpit lump causes: 

• Swollen Lymph Nodes: Enlargement of lymph nodes, which can occur due to infections, allergy or sometimes cancer, can produce a noticeable lump in the armpit¹. 
• Bacterial or Viral Infections: Bacterial infections can cause lumps filled with pus, known as boils or abscesses, which can be red, inflamed, warm and painful³. Viral infections like herpes infection, HIV/AIDS, or mononucleosis infection can also cause armpit lumps¹.
• Hair issues: Ingrown hair can produce pimple like growths under the skin along with redness and itchiness, as a result of shaving or waxing. Chronic skin conditions like hidradenitis suppurativa that can cause inflammation and pus formation around the hair follicles also cause armpit lumps^2,4.
• Cysts: Cysts like epidermal cysts can cause swelling as they hold a fluid-filled sac under the skin², which are usually harmless but can also produce painful lumps¹.
• Lipomas: These are lumps filled with fatty tissues under the chest, back, shoulders, arms or neck, which are usually harmless^1,2.
• Inflammation or Allergic Reactions: Allergic reactions such as after using antiperspirants or inflammatory conditions like sarcoidosis or lupus can also cause armpit lumps^1,2.
• Certain Medicines or Vaccines: These may cause swelling of the lymph nodes by activating and gathering immune cells as an immune response, making them temporarily enlarged⁵, such as due to covid vaccines or medicines like phenytoin, allopurinol or certain antibiotics².
• Some Types of Cancers: Spread of cancers from adjacent areas such as breast cancer or certain blood or lymphatic cancers can cause swelling of lymph nodes as they trap the cancerous tumour cells, which can be felt as hard, immovable armpit lumps^1,2.

Symptoms of Armpit Lumps

As the lump under the armpit can arise from a variety of causes, each cause can put forward different symptoms. The following are some symptoms that you may experience if you have an armpit lump 

• A visible or palpable lump, which arises in different sizes and shapes² 
• Can feel pain or tenderness over the lump area^1,2 
• Redness or warmth can be felt around the lumps² 
• Soft or hard texture, where the lumps can be movable or fixed² 
• Rashes or irritation (for allergic lumps)^2,4 
• Fever, sore throat, cough or runny nose (for infectious lumps)² 
• Tiredness or weight loss² (might indicate severe issues like cancer) 

Note: The symptoms of lumps, if persisting for a while, should not be ignored, as they can also indicate dangerous conditions like HIV or certain cancers. Therefore, consult your doctor if the symptoms are not resolving or getting worse than before. 

Diagnosis of Armpit Lumps 

Doctors typically use a combination of clinical evaluation and tests to determine armpit lump causes. These include: 

• Medial History Review: The doctor might ask you questions regarding: 
  • First noticing of the lump 
  • Changes in size or shape since it formed 
  • Breastfeeding 
  • Other symptoms like pain, weight gain or loss, fever, fatigue, or infections¹
  • Use of medications or vaccines 
  • Family history for conditions like breast issues or cancer 
• Physical Examination by a Doctor: The doctor will perform a physical examination. He might access: 
  • Shape, sizeand texture (soft, hard, or firm) 
  • Mobility (moving or fixed at a position 
  • Location (chest, breast, neck or arms)² 
• Laboratory Tests: The doctor might suggest performing a throat swab or blood tests to check the following: 
  • Signs of infection (increased white blood cells) 
  • General health: to understand inflammatory conditions or immune system-related diseases (perform a full blood count) 
  • Liver health: to understand whether it is medication related² 
• Imaging Tests: The doctor might suggest imaging tests to visualise the lumps internally; these include the following: 
• Ultrasound: Uses high frequencies of sound waves to examine breasts or armpits 
• Mammogram: Uses low doses of X-rays to examine breasts⁶ 
• Computer Tomography (CT): Uses multiple X-rays and computer processing to create detailed cross-sectional images of the body⁷ 
• Magnetic Resonance Imaging (MRI): Uses strong magnetic fields and radio waves to produce detailed images of soft tissues such as tumours or lymph nodes⁸ 
• X-Ray: Uses a small amount of radiation to take pictures inside the body and check nearby chest or breast areas⁹
• Biopsy: The doctor might remove a small portion of the lump with a needle and then send it to the laboratory for testing, mostly done if any abnormal images are detected in imaging tests^2,6. This can help diagnose the underlying cause and distinguish between cancerous and non- cancerous lumps. 

Treatment Options for Armpit Lump

Although some types resolve themselves, certain types might require medical/surgical management. Armpit lump treatment is employed by doctors based on the causes and can include the following: 

• Antibiotics or Antivirals: The doctor might prescribe antibiotics for bacterial infections. If the infection is viral, then he might give you antiviral medicines². This might help reduce swelling, pain and inflammation. 
• Draining: The doctor might cut open your boil or abscess and remove pus from the wound. This might promote faster healing³. 
• Treating Underlying Conditions: The doctor might suggest the following treatments: 
• Medicines²: To treat conditions like inflammatory diseases, which might reduce inflammation and severity; to treat dermatology problems, which might reduce irritation and itching. 
• Surgery: To remove lipomas or cysts which cause discomfort; to remove cancer cells, if cancer is detected^6,10.
• Chemo or Radiation Therapy: To treat several types of cancers like lymphatic cancer (lymphoma), breast cancer, blood cancer, etc. 

Home Remedies for Armpit Lumps

While medical treatment is the cornerstone of management for lumps that don’t resolve spontaneously or are bothersome, the following armpit lump home remedies may be tried: 

• Warm Compress: Apply a warm cloth; it might reduce pain and swelling and promote healing³.
• Maintain Hygiene: Keep the area clean and dry; it might reduce the occurrence of infections. 
• Avoid Irritants: Pause shaving temporarily;⁴ or the use of antiperspirants;¹ these might reduce further irritation. 
• Wear Loose Clothes: Choose soft breathable clothes;¹¹ might reduce friction and irritation. 
• Use Mild Antiseptic: Apply a small amount of antiseptic using cotton; might help reduce infections¹². 

Note: Home care tips should be followed only alongside medical treatment, if advised. Avoid solely relying on them as they cannot heal the problem permanently. Although some cases resolve by themselves, consulting a doctor is very important to understand how to cure an armpit lump, especially if the lump persists, grows, or becomes painful. 

Possible Complications

A lump under the armpit, if left untreated, can worsen the condition. The following are possible complications of armpit lumps. 

• Spread of infections: Infection can spread to nearby tissues, which can increase the severity of the condition¹². 
• Abscess Formation: Pus accumulation may occur, causing painful lumps which might need drainage³. 
• Reoccurrence: Some lumps, particularly cystic ones, may come back over time¹³. 
• Lymphoedema: Lymph fluid can accumulate between the skin and muscle; a common complication of cancer treatment, which might increase the risk of cellulitis (serious bacterial infection)¹⁴. 
• Restricted Motion: Pain and discomfort may interfere with daily activities and limit the range of motion. 
• Systematic Illness: Indicate serious conditions such as breast cancer, lymphoma, HIV, herpes infection, hepatitis, or mononucleosis^1,2.

Preventive Tips

Lump under the armpit caused by conditions like infections, ingrown hair, etc., can be avoided by following certain tips such as the following: 

• Keep the underarm area clean and dry, and wash your hands often² 
• Avoid sharing personal hygiene equipment with others 
• Use clean razor and exfoliate before shaving and apply moisturiser once done⁴ 
• Avoid being intimate with people who have infections² 
• Avoid using irritants like antiperspirants¹
• Perform regular health check-ups and get necessary vaccinations² 
• Avoid smoking and maintain healthy weight^11,12 
• Stay well hydrated 

Note: These are just general tips which might help reduce the occurrence of lumps; following these doesn’t necessarily mean that someone may not get related infections or conditions. 

Myths and Facts About Armpit Lumps

Armpit lumps are often surrounded by common misconceptions, but understanding the facts can help reduce unnecessary worry and ensure timely medical care. The following are a few common myths which are widespread:

When to See a Doctor?

There are certain signs that you should not ignore if you have armpit lumps. Consult a doctor immediately: 

• If the lumps under the arms interfere with your day-to-day activities 
• If the lumps under armpits are not resolved within 3 weeks² 
• If the lumps start growing and you experience new pain 
• If the pain around the lumps gets worse¹⁰ 
• If you experience sudden weight loss and weakness 
• If you get unexpected bruising and bleeding 
• If you start sweating excessively 
• If you are having severe fever, chills, throat pain, and rashes along with lumps²
• If the medications no longer reduce the symptoms 

Also Read: Home Remedies for Dark Underarms

Conclusion

Armpit lumps are a common concern and are often harmless, usually caused by infections, irritation, or swollen lymph nodes. However, some cases may indicate underlying conditions that require medical attention. Understanding the causes, symptoms, and treatment options can help you respond appropriately. While simple home care may help in minor cases, it is important to consult a doctor if the lump persists, grows, or is associated with other symptoms. Early evaluation provides peace of mind and helps get timely and appropriate treatment when needed. 

Frequently Asked Questions (FAQs)

References

1. Armpit Lump. 2025. doi: https://medlineplus.gov/ency/article/003099.htm 

2. Lump Under Armpit. 2025. doi: https://www.healthdirect.gov.au/lump-under-armpit 

3. Boils and Curbuncles. 2022. doi: https://www.ncbi.nlm.nih.gov/books/NBK513141/ 

4. Ingrown Hair. 2023. doi: https://www.healthdirect.gov.au/ingrown-hair 

5. Ah-Thiane L, Ferrer L, Maucherat B, et al. Vaccine-Related Lymph Nodes: The Emerging Pitfalls of 18F-Fluorocholine and 68Ga-PSMA-11 PET/CT in the Era of COVID-19 Vaccination. Clin Nucl Med. 2022;47(7):575-582. doi:10.1097/RLU.0000000000004190. https://pubmed.ncbi.nlm.nih.gov/35675134/

6. Tests for Breast Cancer. 2023. doi: https://www.cancerresearchuk.org/about-cancer/breast-cancer/getting-diagnosed/tests

7. Computer Tomography. US FDA. https://www.fda.gov/radiation-emitting-products/medical-x-ray-imaging/computed-tomography-ct

8. MRI Scan. 2014. doi: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/mri-scan

9. X-Ray. doi: https://medlineplus.gov/xrays.html 

10. Lipoma. 2025. doi: https://www.healthdirect.gov.au/lipoma

11. Hidradenitis Superativa. doi: https://medlineplus.gov/hidradenitissuppurativa.html

12. Hidradenitis suppurativa (HS). 2023. doi: https://www.nhs.uk/conditions/hidradenitis-suppurativa/

13. Weir CB, J N, Hilaire. Epidermal Inclusion Cyst. 2023. doi: https://www.ncbi.nlm.nih.gov/books/NBK532310/ 

14. Lymphedema. 2024. doi: https://www.cancer.gov/about-cancer/treatment/side-effects/lymphedema 

15. What Are the Symptoms of Lymphoma. doi: https://www.canceraustralia.gov.au/cancer-types/lymphoma/what-are-symptoms-lymphoma 

16. Skin Lumps. 2025. doi: https://medlineplus.gov/ency/article/003279.htm

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