What are lymph nodes?
The lymph system is an aspect of the immune system. It’s a group of lymph vessels and lymph nodes. There are about 800 lymph nodes scattered throughout your body, with more than a third located in the head and neck. Lymph fluid, which has white blood cells to fight infection, moves through lymph vessels. The lymph nodes act as filters for diets and foreign substances. When you have an infection, injury, or cancer, lymph nodes swell up as they filter out problem substances.
Swollen lymph nodes are a sign that something is going on. But swelling alone isn’t enough to tell you exactly what it is.
Single vs. generalized lymphadenopathy
Generally, there’s normally one part of a swollen lymph node, such as the neck, underarm or groin. In some cases, there are different areas of swollen lymph nodes, which include the neck, underarm or groin. When there are different areas of swollen lymph nodes, it is called generalized lymphadenopathy.