Swollen Lymph Nodes What are lymph nodes? Lymph nodes are small,
bean-shaped glands throughout the body. They are part of the
lymphatic system, which carries fluid (lymph fluid), nutrients,
and waste material between the body tissues and the bloodstream.
The lymphatic system is an important part of the immune system,
the body's defense system against disease. The lymph nodes
filter lymph fluid as it flows through them, trapping bacteria,
viruses, and other foreign substances, which are then destroyed
by special white blood cells called lymphocytes. Lymph nodes may
be found singly or in groups. And they may be as small as the
head of a pin or as large as an olive. Groups of lymph nodes can
be felt in the neck, groin, and underarms. Lymph nodes generally
are not tender or painful. Most lymph nodes in the body cannot
be felt. What causes swollen lymph nodes? Lymph nodes often
swell in one location when a problem such as an injury,
infection, or tumor develops in or near the lymph node. Which
lymph nodes are swol