Lymph nodes are small, bean-shaped structures that are part of the body’s immune system. These glands act as filters, trapping foreign substances like bacteria, viruses, and abnormal cells from the lymphatic fluid. Found throughout the body, lymph nodes are clustered in areas such as the neck, groin, and armpits. They contain immune cells, including white blood cells, that identify and destroy harmful invaders.
Identifying Swollen Lymph Nodes
Checking your armpit lymph nodes involves a systematic approach. Begin by sitting or standing comfortably, with your arm slightly lifted and relaxed. Place the fingertips of one hand high into the opposite armpit.
Using the flats of your fingers, gently but firmly press and roll the tissue against your chest wall. Move your fingers across the entire armpit area, covering the front, back, and inner upper arm. A normal lymph node is small, pea-sized or smaller, and may be difficult to feel. They should feel soft, pliable, and movable under the skin.
In contrast, a swollen lymph node will feel larger, from pea to grape-sized or larger. They may feel firmer or more rubbery than surrounding tissue. Swollen nodes can also be tender or painful, especially if inflamed by infection. Comparing both armpits can be helpful, as they exist in pairs, and often only one side is affected.
Common Reasons for Swelling
Swollen lymph nodes in the armpit signal an active immune response. The most frequent cause is an infection, where lymph nodes enlarge as immune cells multiply to fight pathogens. This includes bacterial infections like cellulitis or cat scratch disease. Viral infections, such as the common cold, flu, mononucleosis, or HIV, can also cause swelling.
Beyond infections, inflammatory conditions can cause swelling. Autoimmune diseases like rheumatoid arthritis or lupus can cause temporary enlargement as part of a systemic immune reaction. A reaction to vaccinations is also a cause of swollen lymph nodes. When a vaccine is administered in the arm, the immune system activates nearby lymph nodes to produce white blood cells, causing swelling that typically resolves within a few weeks.
While less common, swollen armpit lymph nodes can also indicate more serious conditions, such as cancers. Lymphoma, a cancer of the lymphatic system, can cause enlargement. Cancers from other parts of the body, particularly breast cancer, can also spread to the armpit lymph nodes, causing swelling. In such cases, nodes may feel hard and immobile.
When to Consult a Healthcare Professional
While many instances of swollen armpit lymph nodes are temporary, certain characteristics warrant medical evaluation. Consult a healthcare professional if the swelling persists for more than two to four weeks or grows. Lymph nodes that feel hard, rubbery, or are fixed in place should be examined.
Unexplained swelling, especially without an obvious infection or recent vaccination, warrants a doctor’s visit. Pay attention to any accompanying symptoms. These include unexplained fever, night sweats, or significant weight loss. Other concerning signs are a persistent cough, fatigue, or skin changes over the swollen node, such as redness or warmth. If the swollen node is very painful or causes difficulty moving your arm, seek medical advice.