What to Do About Swollen Lymph Nodes Under the Armpit

Swollen lymph nodes under the armpit, also known as axillary lymphadenopathy, are a common condition that many people experience at some point in their lives. While it can be concerning, most cases are not serious and are often linked to benign causes such as infections or immune responses.

Common Causes of Axillary Lymph Node Enlargement

Lymph nodes act as filters for harmful substances in the body and can swell when fighting off infections or other threats. The majority of swollen lymph nodes in the armpit area are due to benign reactive hyperplasia, which means the lymphatic tissue has increased in response to a local infection, minor injury, or skin irritation—such as from shaving, an infected hair follicle, or even a small cut.

Painful Swelling: Usually a Sign of Inflammation

If the swollen node is tender or painful to the touch, it typically indicates an active inflammatory process. This could stem from bacterial or viral infections in the arm, hand, or nearby skin. In such cases, treatment focuses on addressing the underlying cause. Doctors may recommend a course of antibiotics like amoxicillin, cephalosporins, azithromycin, or roxithromycin, depending on the suspected pathogen.

During treatment, it's advisable to avoid irritants such as spicy foods, cold beverages, or harsh skincare products that might exacerbate inflammation. Rest, hydration, and warm compresses can also help reduce discomfort and support recovery.

When to Be Concerned: Painless Lymph Node Enlargement

A more worrisome sign is a painless, firm, and persistently enlarged lymph node. Unlike inflamed nodes, these do not tend to shrink over time and may indicate something more serious, such as lymphoma (a type of blood cancer) or metastatic cancer from another site—commonly breast, lung, or melanoma.

Next Steps for Persistent or Suspicious Swelling

If a lymph node remains enlarged for more than two weeks without signs of infection, further medical evaluation is essential. A healthcare provider may order imaging tests such as an ultrasound or MRI and recommend a biopsy—either fine-needle aspiration or surgical excision—to examine the tissue under a microscope.

Accurate diagnosis through pathology allows doctors to determine whether the swelling is due to cancer, autoimmune disease, or another systemic condition. Treatment will then be tailored accordingly, ranging from watchful waiting to chemotherapy, radiation, or surgery.

Prevention and When to Seek Help

Maintaining good hygiene, promptly treating skin wounds, and performing regular self-exams (especially breast self-checks for women) can help catch issues early. However, if you notice any unexplained lump in your armpit—especially one that's growing, hard, or immovable—it's important to consult a physician without delay.

Early detection significantly improves outcomes, particularly in cases involving malignancy. Don't ignore persistent changes; timely medical assessment is key to peace of mind and effective care.