Lymph nodes, also known as lymph glands, are not caused by a single event, but rather are present as part of the body's normal anatomy. They are small, bean-shaped structures that are a vital part of the body's immune system. What causes lymph nodes to become swollen (a condition called lymphadenopathy) is a different matter.
Causes of Swollen Lymph Nodes
Swollen lymph nodes are typically a response to an infection or illness. The most common culprits are:
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Bacterial or viral infections: These are the most frequent causes. Infections in the area surrounding the lymph node cause the node itself to swell as it works to fight the infection. Examples include colds, the flu, ear infections, and strep throat. [Source: Mayo Clinic, Cleveland Clinic, Healthline]
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Other infections: Various other infections can lead to swollen lymph nodes, including mononucleosis, and infections of the mouth, gums, or teeth. [Source: Mount Sinai, Healthline]
Less common, but still significant causes include:
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Cancer: In rare cases, swollen lymph nodes can be a sign of cancer. The cancer may have originated in the lymph nodes themselves (lymphoma) or spread from another part of the body. [Source: Mayo Clinic, Cancer.org]
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Autoimmune disorders: Conditions like rheumatoid arthritis can cause lymph node swelling. [Source: AAFP]
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Medications and other treatments: Certain medications and medical procedures can trigger swollen lymph nodes as a side effect. [Source: AAFP]
Understanding the Role of Lymph Nodes
It's crucial to understand that lymph nodes themselves aren't something that is caused; they exist naturally. It's their swelling (lymphadenopathy) that requires attention. They filter lymph fluid, a fluid containing waste and immune cells, removing harmful substances and helping the body fight off infection. When they swell, it's often an indication that the body is actively combating an infection or dealing with an underlying health issue. [Source: Mayo Clinic, NHS] The size and location of the swollen nodes, along with accompanying symptoms, help doctors diagnose the underlying problem.
