What are lymph nodes and why is it important that I know about them? Admittedly, this is not a question I get every day. Lymph nodes, for those of you chomping at the bit to find out the answer, serve both as the body’s trash cans and monitoring systems.

Whenever something in the body is inflamed or infected, the body mounts an immune response with both cells (including lymphocytes) and chemicals (most with difficult to spell and pronounce names). The cells often migrate from and to the lymph nodes. Those nodes near the problem area will enlarge and, in acute processes such as infection, will be tender as well. For example, throat infections such as strep throat will cause the lymph nodes in the front of your neck to enlarge. A toe infection will lead to enlarged nodes behind your knee and in your groin.

When a doctor does her exam, she will be able to identify enlarged nodes. The question then becomes what caused the nodes to become large. In the case of groin nodes, most of us have enlarged but non tender nodes. Thus, enlarged but non painful nodes there are not necessarily significant. However, if she finds large, tender nodes in your neck, she would look in your mouth for infection.

Sometimes lymph nodes are large but not at all tender. If these nodes are hard and don’t move easily, concern would be raised for cancer in a location nearby or if nodes are large in several areas, for either a blood cancer such as lymphoma or leukemia or a cancer which has spread (metastasized). Other conditions associated with large nodes include autoimmune diseases such as Lupus or colitis, chemical exposure and certain medications.

If you feel that your lymph nodes are too big, see your doctor.