Published on: 6/18/2025
What could cause a swollen lymph node in the right armpit?
A swollen lymph node in the right armpit can be caused by infections, immune responses, or, less commonly, cancers, and should be evaluated if it persists or is accompanied by other symptoms.
Explanation
Lymph nodes in the armpit help filter bacteria, viruses, and other harmful substances. Swelling occurs when they are active or irritated. Common causes include:
Infections: Such as skin infections, respiratory infections, or infections near the arm or breast. Immune responses: Reaction to vaccines or minor injuries. Localized inflammation: Due to irritation or allergic reactions in the nearby area. Cancers: Less commonly, swollen lymph nodes can be due to lymphoma or breast cancer. Other causes: Autoimmune diseases like lupus or rheumatoid arthritis.
If the swollen lymph node lasts more than 2 weeks, grows, becomes hard or fixed, or is accompanied by unexplained weight loss, night sweats, or fever, it’s important to see a healthcare provider.
(References)
- Görkem SB, & O'Connell AM. (2012). Abnormal axillary lymph nodes on negative mammograms. Diagnostic and interventional radiology (Ankara, Turkey), 22415745.
- Hermansyah D, Al Anas M, Firsty NN, & Alianto R. (2022). Cat-Scratch Lymphadenitis Presenting with Right Upper .... Medical archives (Sarajevo, Bosnia and Herzegovina), 36937617.
- Fujii T, Kimura M, Yanagita Y, Koida T, & Kuwano H. (2003). Tuberculosis of axillary lymph nodes with primary breast .... Breast cancer (Tokyo, Japan), 12736574.
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