Overview

Swollen lymph nodes under the arm, also known as axillary lymphadenopathy, occur when the lymph nodes located in the armpit become enlarged. This swelling can be a natural response to infection, inflammation, or other underlying medical conditions. Lymph nodes are part of the body’s lymphatic system, which plays a crucial role in filtering harmful substances and fighting infections. While swollen lymph nodes are often harmless and temporary, they can sometimes indicate more serious conditions such as autoimmune diseases or cancers.

Causes

There are several possible causes of swollen lymph nodes under the arm:

• Infections: Bacterial or viral infections like the flu, mononucleosis, or skin infections near the arm can cause temporary swelling.
• Localized infections: An infection or injury to the arm, breast, or hand can lead to localized lymph node enlargement.
• Vaccinations: Recent vaccinations, especially COVID-19 or flu shots, can trigger a reactive swelling of the axillary nodes.
• Autoimmune diseases: Conditions like lupus or rheumatoid arthritis can cause chronic inflammation and lymph node swelling.
• Cancer: Breast cancer, lymphoma, or melanoma can cause hard, persistent swelling in the underarm area.
• Medications: Certain medications, such as antiseizure drugs or antibiotics, may cause lymph node enlargement as a side effect.

Symptoms

Swollen lymph nodes under the arm can be accompanied by various symptoms, depending on the underlying cause:

• Tenderness or pain in the armpit area.
• Visible or palpable lump under the skin of the armpit.
• Redness or warmth over the swollen area, especially if an infection is present.
• Fever and chills in cases of systemic infections.
• Fatigue or general feeling of illness.
• Unexplained weight loss, night sweats, or persistent fever, which may indicate lymphoma or other cancers.

Diagnosis

To determine the cause of swollen lymph nodes under the arm, a healthcare provider may perform:

• Physical examination: Assessing the size, texture, and tenderness of the swollen lymph nodes.
• Medical history: Asking about recent infections, vaccinations, injuries, or other health conditions.
• Blood tests: To check for infections, autoimmune markers, or abnormal blood cell counts.
• Imaging tests: Ultrasound, mammogram, or MRI may be used to examine the lymph nodes and surrounding tissues more closely.
• Biopsy: If cancer is suspected, a needle or surgical biopsy may be performed to analyze lymph node tissue.

Treatment

Treatment for swollen lymph nodes under the arm depends on the underlying cause:

• Infections: Bacterial infections are treated with antibiotics, while viral infections typically resolve on their own with supportive care.
• Anti-inflammatory medications: Pain relievers and anti-inflammatory drugs can reduce pain and swelling.
• Warm compresses: Applying a warm compress to the area can help soothe discomfort and promote drainage.
• Treatment of underlying conditions: Autoimmune diseases are managed with medications like corticosteroids or immunosuppressants.
• Cancer treatment: If cancer is diagnosed, treatment may include surgery, chemotherapy, radiation therapy, or targeted therapies depending on the type and stage.

Prognosis

The prognosis for swollen lymph nodes under the arm varies based on the cause. Most cases due to infections resolve within a few weeks with proper treatment. Reactive lymph node swelling from vaccines or minor infections typically improves without complications. However, persistent, hard, or rapidly growing lymph nodes require prompt medical evaluation to rule out serious conditions like cancer. With early diagnosis and appropriate treatment, even more serious causes can often be managed effectively, leading to improved outcomes and recovery.