What is lymphadenopathy and how serious is this?

Lymphadenopathy refers to the presence of swollen lymph nodes. Lymph nodes are small bundles of white blood cells. One of the ways the body's immune system responds to infections and inflammation is to greatly increase the number of white cells in the lymph nodes causing them to swell.
We have lymph nodes throughout our bodies. The parts of the body where people and their doctors can see or feel swollen lymph nodes include the neck, armpit, and groin areas. Most often swollen lymph nodes are caused by an infection, an autoimmune disease like lupus, or some other non-cancerous condition. Less commonly, lymph nodes enlarge related to cancer.