You have hundreds of the small, round, or bean-shaped glands all over your body. Most are spread out, but some are found in groups in a few major places, like your neck, under your arm, and in your chest, belly, and groin. You might be able to feel some of the clusters in those areas as little bumps.
How Do They Work?
Your lymph nodes are connected to one another by lymph vessels (tubes that run through your body like veins). They carry lymph fluid -- a clear, watery liquid that passes through the nodes.
As the fluid flows through, cells called lymphocytes help protect you from harmful germs.
There are two kinds of lymphocytes -- B-lymphocytes (or B-cells) and T-lymphocytes (or T-cells).
- B-cells make antibodies that attach to germs and let your immune system know they need to be killed off.
- T-cells have a couple of jobs. Some destroy germs, while others keep track of immune cells. They let your body know when to make more of certain kinds and less of others.
Lymph fluid also carries protein, waste, cellular debris (what’s left after a cell dies), bacteria, viruses, and excess fat that are filtered by the lymphatic system before it’s dumped back into the bloodstream.
Swollen Lymph Nodes
When there’s a problem in your body, like an illness or an infection, your lymph nodes can swell. (This usually happens only in one area at a time.) It’s a sign that more lymphocytes are in action than usual, trying to kill off germs.
You may notice this most often in the glands in your neck. That’s why your doctor feels the area under your jawbone. They’re checking to see if those glands are bigger than usual or tender.
Many things can make your lymph nodes swell. It might be something like a cold or the flu, an ear infection, or an abscessed tooth. Much less often, it can be a sign of something more serious, like tuberculosis or cancer.