What Does Lymphadenopathy Mean?

MedlinePlus says so directly. The medical name for swollen lymph nodes is lymphadenopathy. NCI defines it as disease or swelling of the lymph nodes.

That is the whole content of the word. Someone saw a node that was bigger than expected, or that looked unusual, and wrote it down.

Lymph nodes are part of your immune system. MedlinePlus says they help the body recognise and fight germs, infections and other foreign substances. Swelling is often that system doing its job.

MedlinePlus is unambiguous: infections are the most common cause of swollen lymph nodes.

Its list is longer than people expect:

• an abscessed or impacted tooth.
• an ear infection.
• colds, flu and other infections.
• inflamed gums.
• mononucleosis, mouth sores or tonsillitis.
• skin infections and tuberculosis.
• sexually transmitted infections.

Immune conditions are also on the list, including HIV and rheumatoid arthritis. So are certain medicines. MedlinePlus names seizure medicines such as phenytoin, and typhoid immunization.

A dental problem is a more likely explanation for a neck node than a rare cancer. That is not reassurance for its own sake. It is the order the evidence puts them in.

This is the single most useful distinction on the page, and MedlinePlus states both halves.

Swollen nodes that appear suddenly and are painful are usually due to injury or infection. Slow, painless swelling may be due to cancer or a tumor.

MedlinePlus adds a detail that saves a lot of worry. Painful nodes are generally a sign the body is fighting an infection. The soreness usually goes within a couple of days. But the node may not return to its normal size for several weeks.

So a node that is still faintly there a fortnight later is not automatically a problem.

MedlinePlus says which nodes swell depends on the cause and the body parts involved. Nodes you can feel with your fingers sit in the groin, the armpit, the neck, under the jaw and chin, behind the ears, and at the back of the head.

Location matters because nodes drain the area near them. It also matters in cancer for a specific reason MedlinePlus gives: a nearby lymph node is often the first place a cancer spreads.

Size is used differently in children. MedlinePlus says a node in a child counts as enlarged above 1 centimeter, about 0.4 inches.

MedlinePlus names leukemia, Hodgkin disease and non-Hodgkin lymphoma among the cancers that cause swollen nodes, and says many other cancers may also do so.

It gives a specific list of reasons to contact a provider:

• nodes that do not get smaller after several weeks, or keep growing.
• nodes that are red and tender.
• nodes that feel hard, irregular, or fixed in place.
• fever, night sweats, or weight loss you cannot explain.
• any node in a child larger than 1 centimeter.

Hard, irregular and fixed is the phrase worth remembering. A node that moves under your fingers behaves differently from one that does not.

MedlinePlus lists the usual next steps. Blood tests, including a complete blood count with differential, and liver and kidney function tests. A chest x-ray. A CT scan of the chest and abdomen. And, when the answer still is not clear, a lymph node biopsy.

Treatment then depends entirely on the cause, which is the whole point. Nobody treats lymphadenopathy. They treat whatever is producing it.

Is a Swollen Lymph Node a Sign of Cancer? covers this from the symptom side, and What Does Enlarged Lymph Node Mean on a Scan? covers the imaging wording.

• MedlinePlus — Swollen lymph nodes
• NCI Dictionary of Cancer Terms — lymphadenopathy