Enlarged lymph nodes, also known as swollen glands, which usually develop as a response to infection
Swelling of the lymph nodes is a common symptom of many conditions. A single node, a group of nodes, or all the lymph nodes may be affected. Lymph nodes most commonly become swollen in response to a bacterial or viral infection. You are more likely to notice a swollen lymph node in the neck, groin, or armpit, because the nodes in these areas lie closest to the skin.
Swelling of a single node or group of lymph nodes is often due to a localized bacterial infection. For example, swollen lymph nodes in the neck are commonly caused by throat infections. In most cases of lymphadenopathy due to an infection, the swelling usually subsides when the infection clears up. Swollen lymph nodes that are the result of an infection are often painful.
Persistent swelling of many, or all, of the lymph nodes may be a result of some types of cancer, such as breast cancer, lymphoma, or leukaemia. Swollen lymph nodes due to cancer are not normally painful.
You should consult your doctor if a swelling is persistent or if you are worried about accompanying symptoms.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.