Get to Know Your Lymph Nodes

These tiny, bean-shaped organs are part of your body’s defenses -- your immune system. A watery liquid called lymph runs through your body and brings bacteria and other harmful things to the nodes, where white blood cells attack and kill them.

They’re connected to one another through tiny tubes called lymph vessels. These tubes carry the fluid to and from the nodes.

Groups of them, called clusters, are in your neck, under your arms, and in your groin. You might be able to feel them as little bumps in those areas. But you’d never know that they’re also in your stomach and chest.

Lymph nodes have lots of help, thanks to your spleen, tonsils, adenoids, and thymus. Together, these organs make up your lymphatic system.

Your spleen, tonsils, and adenoids fight bacteria and viruses that cause infection or sickness. When you’re young, your thymus makes the kind of white blood cells that live in lymph nodes and kill germs.

This small organ is in your chest, just behind your breast bone. It’s busy when you’re young -- and biggest when you’re in puberty (about 1 ounce). Over time, it gets smaller and is replaced by fat tissue.

Just like your appendix, it can burst and if so, you’ll need to have it taken out immediately. Other reasons it might need be removed include infection, a blood disorder, a cyst, or a tumor. You’re more likely to get infections without your spleen.

You also can live without your tonsils or adenoids. The long-term effects of having those taken out are still being studied.

When your doctor feels the sides of your neck, around your throat, they're checking your lymph nodes to see if they’re swollen, sore, warm, or firm. Other areas you might notice these signs of infection or illness are in the nodes under your armpit or in your groin.

Swollen lymph nodes usually are triggered by a virus, like the common cold, or bacteria, and they return to normal once you’re well and any infection is gone.

Normally, your white blood cells die when they get old, and your body makes new ones. If you have lymphoma, these cells grow and divide instead. Your lymph nodes get crowded and swell. Over time, they’re less able to fight infections.