Finding an armpit lump can be concerning, but many are not serious. These common lumps arise from various sources, from temporary irritations to internal processes. Understanding their potential origins can help guide next steps.
Common Benign Causes of Armpit Lumps
The most frequent cause of an armpit lump is a swollen lymph node, known as lymphadenopathy. Lymph nodes are small, oval structures of the immune system. They swell when fighting infections from bacteria, viruses, or other foreign invaders, leading to a noticeable lump. Common infections like a cold, flu, strep throat, or skin infections can cause temporary lymph node swelling. Allergic reactions or vaccinations, such as the COVID-19 vaccine, can also lead to temporary swelling.
Another common type of armpit lump includes cysts, such as sebaceous or epidermoid cysts. These fluid-filled sacs develop under the skin and can become sore or red if infected. Ingrown hairs or folliculitis, an infection of hair follicles, can also result in painful, localized bumps in the armpit. These often occur after hair removal practices like shaving.
Lipomas are another benign cause, appearing as harmless, fatty growths that are soft and movable under the skin. These fat cell collections typically do not require treatment unless bothersome. Hidradenitis suppurativa is a chronic skin condition causing painful, boil-like lumps and abscesses, commonly found in areas with sweat glands, including the armpits. These lumps can rupture, oozing pus and sometimes blood, and may form tunnels under the skin. Fibroadenomas, non-cancerous fibrous tissue growths associated with breast tissue, can also extend into the armpit and present as a lump.
Less Common but Serious Causes
While most armpit lumps are benign, some less common causes warrant medical evaluation. Persistent or severe infections can lead to prolonged lymph node swelling. These include bacterial infections like cat scratch disease, or systemic infections such as tuberculosis and certain fungal infections. Autoimmune diseases like lupus can also result in swollen lymph nodes.
Lymphoma, a cancer of the lymphatic system, can manifest as an armpit lump. It often causes swollen lymph nodes in the neck, groin, or armpit, which may be painless. These enlarged nodes can feel smooth, round, and rubbery. Breast cancer is another serious cause, as it can spread to the axillary lymph nodes in the armpit. These nodes are often the first location where breast cancer cells may travel.
Leukemia, a cancer of blood-forming tissues, can also be associated with enlarged lymph nodes in the armpit. In leukemia, abnormal white blood cells accumulate in the lymph nodes, causing swelling. Other types of cancer can also metastasize to the axillary lymph nodes from distant parts of the body. This occurs when cancer cells enter the lymphatic system or bloodstream and travel to these nodes.
Key Indicators for Medical Consultation
Understanding when to seek medical attention for an armpit lump is important. Consult a doctor if the lump is larger than a pea, feels hard or firm, is immovable, or has an irregular shape. A painless lump can also be a concerning sign, as some serious conditions may present without discomfort.
Changes in the lump over time also serve as important indicators. A lump growing in size, changing shape, or persisting for more than a few weeks should be evaluated by a healthcare professional. Benign lumps typically resolve or remain stable, while persistent or evolving lumps may suggest an underlying issue.
Additionally, the presence of other symptoms accompanying the armpit lump warrants immediate medical attention. These associated symptoms can include unexplained weight loss, persistent fever, drenching night sweats, or unusual fatigue. Skin changes over the lump, like redness, dimpling, or warmth, can indicate infection or other issues. Any new lumps or changes in the breast tissue, particularly for women, should also prompt medical review. Consulting a healthcare professional is advisable if any of these indicators are present or if general concern about the lump persists.
The Diagnostic Journey
When visiting a doctor for an armpit lump, the diagnostic process begins with a thorough medical history and physical examination. The doctor will ask detailed questions about when the lump was first noticed, how it has changed, and any accompanying symptoms. During the physical examination, the doctor will gently press on the lump and the surrounding areas, including other lymph node regions, to assess its size, texture, mobility, and tenderness.
Following the initial examination, the doctor may recommend imaging tests to gain a clearer view of the lump’s internal structure. Common imaging techniques include an ultrasound and a mammogram, particularly if breast cancer is a consideration. These tests help determine if the lump is solid or fluid-filled and provide more information about its characteristics.
If the imaging results are inconclusive or suggest a potentially serious cause, a biopsy may be performed. This procedure involves taking a small tissue sample from the lump for laboratory analysis. The tissue is then examined under a microscope by a pathologist to determine the nature of the cells and arrive at a definitive diagnosis. Based on the findings from these tests, the doctor will provide a diagnosis and discuss appropriate management or treatment options, which can range from observation to medication or surgical intervention.