Lymph nodes in the armpit, known as axillary lymph nodes, often become a source of concern when they swell. A common misconception is that these small structures can “burst.” Understanding their true nature and function, and what causes them to change, can provide clarity and reduce unnecessary worry.
What are Lymph Nodes and Their Role?
Lymph nodes are small, bean-shaped glands that form an integral part of the body’s lymphatic system. They are strategically located throughout the body, with significant clusters found in areas like the neck, groin, and notably, the armpits. The armpit region typically contains between 20 and 49 axillary lymph nodes. These nodes act as filters for lymph fluid, a clear fluid that circulates throughout the body, collecting waste products, foreign particles, and damaged cells.
Lymph nodes primarily trap harmful substances such as viruses, bacteria, and other pathogens. They serve as a meeting point for immune cells, including lymphocytes (T cells and B cells) and macrophages. Within the nodes, these immune cells identify and destroy foreign invaders, cleansing the lymph fluid before it returns to the bloodstream. This process is fundamental to the body’s defense against infection and disease.
Can Lymph Nodes “Burst”?
The common concern that a lymph node might “burst” like a balloon or a pimple is a misunderstanding of its biological structure and how it reacts to stress. Lymph nodes are encased in a tough, protective outer capsule of connective tissue, providing them with structural integrity. This robust casing prevents them from simply rupturing under normal or even moderately inflamed conditions.
Instead of bursting, a severely infected or inflamed lymph node can sometimes develop into an abscess. An abscess is a localized collection of pus, formed as the body attempts to contain an infection. If such an abscess grows large and the infection is severe, it can eventually erode through the surrounding tissues and potentially rupture, draining its contents to the outside through the skin. This event is a serious medical complication, requiring immediate medical attention to manage the infection and prevent further complications.
Common Causes of Swollen Lymph Nodes in the Armpit
Swelling of lymph nodes, medically termed lymphadenopathy, often indicates that the immune system is actively responding to a threat. In many instances, this swelling is a normal and expected sign of the body fighting off an infection or inflammation. Various factors can lead to the enlargement of axillary lymph nodes.
Infections are a frequent cause.
Bacterial Infections
Bacterial infections like cellulitis, a common skin infection, can cause nearby lymph nodes to swell, often presenting with pain, warmth, and redness in the affected area. Another bacterial cause is cat scratch disease, resulting from a scratch or bite from a cat infected with Bartonella henselae. This condition typically causes tender, enlarged lymph nodes, often in the armpit, sometimes accompanied by a fever.
Viral Infections
Viral infections are also common culprits; for example, infectious mononucleosis, caused by the Epstein-Barr virus, frequently leads to fatigue, sore throat, fever, and swollen lymph nodes in the neck and armpits. General viral illnesses, such as the flu or common cold, can also trigger temporary lymph node swelling.
Beyond infections, inflammatory conditions can result in swollen lymph nodes. Autoimmune disorders, including rheumatoid arthritis and lupus, can cause widespread inflammation that may manifest as enlarged lymph nodes. Certain types of cancer can also cause axillary lymphadenopathy. Lymphoma, a cancer originating in the lymphatic system, often presents as painless, rubbery swollen lymph nodes in areas like the armpit. Breast cancer frequently spreads to the axillary lymph nodes due to their close proximity and their role in draining lymph fluid from the breast tissue.
When to Seek Medical Attention
While swollen lymph nodes are frequently a benign response to infection, certain signs warrant prompt medical evaluation. Consult a healthcare professional if a swollen lymph node in the armpit persists for more than a few weeks without an obvious cause. Nodes that are rapidly growing, feel hard or fixed in place, or are painless without an apparent reason should also be examined by a doctor.
Additional concerning symptoms that should prompt medical attention include:
- Persistent fever
- Unexplained weight loss
- Drenching night sweats
- Unusual fatigue accompanying the swollen nodes
- Any changes in the skin over the lymph node, such as redness or warmth that does not resolve
Consulting a healthcare provider ensures an accurate diagnosis and appropriate treatment plan.