We hear a lot of talk these days about the importance of fighting off illnesses by strengthening the body’s immune system. Key to that disease-prevention mechanism are lymph nodes. Let’s take a deep dive into what they are and how they help us stay healthy.
A single lymph (say “limf”) node is a small structure shaped like a kidney bean. A node is a knot or knob. Inside the body, a lymph node is simply a collection of tissue. Lymph nodes filter harmful substances that travel through the clear lymphatic fluid. The nodes contain lymphocytes – white blood cells – that destroy disease-carrying germs and infections.
There are two kinds of lymphocytes:
- B-cells produce antibodies that attach to germs and signal the immune system to destroy them.
- T-cells so several things: some kill germs, while others monitor the immune cells and tell the body when to increase certain kinds and reduce others.
The network of lymph vessels and nodes collects fluid, waste material, and other unwanted organisms (such as viruses and bacteria) present in the body tissues, outside the bloodstream.
Did you know that there are hundreds of lymph nodes inside you? Lymph vessels connect all the nodes. The neck, armpit (axilla), chest, abdomen, and groin feature clusters of lymph nodes. There are about 20-40 lymph nodes in the axilla alone.
Clusters of lymph nodes are also called lymph glands, groups of cells that secrete a substance for use in the body. The lymphatic system also includes the tonsils, thymus, spleen, and bone marrow.
Lymph fluid bathes the body’s tissue cells after it flows out from capillary walls. Lymph delivers oxygen and other essential nutrients to the cells and removes waste products such as carbon dioxide (CO2) that flow out of the cells.
The lymph vessels prevent fluid build-up and swelling by draining the lymph fluid from around the cells, slowly routing it toward the chest from all around the body, where it accumulates in a large vessel that drains into a blood vessel near the heart. After reaching the heart, the filtered fluid, salts, and proteins are released and enter the bloodstream.
In this way, lymph fluid from the fingers flows toward the chest and joins lymph fluid from the arm. The combined fluid may filter through lymph nodes at the elbow or under the arm.
Lymph from the head, scalp, and face passes down through lymph nodes in the neck. Some lymph nodes reside deep within the body (for example, those between the lungs or around the bowel) to filter fluid local to those areas.
An infection, injury or cancer may interfere with the normal functioning of the lymphatic system. The nearby group of lymph nodes may react by swelling or enlarging as they work overtime to filter out the unhealthy cells. Swollen lymph nodes are a clear sign that a negative medical condition has upset your immune system.
The dimensions of a swollen lymph node range from pea-sized to as large as a cherry. Some oversized glands are painful to touch or hurt after making specific motions or movements.
Ear pain, fever, and enlarged lymph nodes near the ear point to a cold, flu or ear infection. In my case, the sudden appearance of a painless, but otherwise alarming, marble-sized lymph node in my lower left jaw coupled with a painful canker and gum inflammation told me it was time to get my root-canaled tooth pulled to avoid further complications – including cancer.
Usually, lymph nodes swell in one part of the body. Infections such as strep throat and chickenpox, some medications, immune system diseases, and cancers such as lymphoma and leukemia can afflict multiple lymph glands.
Cancer can occur in the lymph nodes in one of two ways: either it starts there (called lymphoma) or it has spread from some other part of the body. Cancer cells that break away from a malignant tumor can travel to other areas of the body through either the bloodstream or the lymph system. In this way, a carcinoma that starts in the throat can wind up in the heart or lungs.
While most of the detached cancer cells die or are killed by the body’s defense system before they can take hold somewhere else, it only takes one or two of them to take up residence in a new area, start multiplying, and form new tumors. The mechanism behind the rise of cancer in a different part of the body is called metastasis.
Never ignore a persistent swollen lymph node. If it doesn’t go away on its own in a few days, seek professional care. Early detection can limit the severity of tuberculosis or cancer that caused the immune system reaction.
Many enlarged lymph glands do go away without treatment. But when they hang around, antibiotics or antiviral medicines may be needed to assist the overactive lymph nodes. Aspirin, ibuprofen, and acemetacin may help reduce pain, inflammation, and fever.
Some cancerous lymph nodes may need to be removed surgically. In some cases, a doctor may order chemotherapy to shrink the tumor.
Since lymph is nearly 95 percent water, one way to bolster your immune system is to drink plenty of H2O. Keep the intestinal tract clear by eating plenty of dietary fiber, omega-3 fatty acids, leafy green vegetables, fat-soluble vitamins A and D, and balanced probiotic supplements.
Exercise and avoiding wearing tight clothing can help the lymph to makes its way back to the heart. Stress is known to weaken the immune system so meditation, yoga, and mindful breathing exercises can all help keep the lymph flowing.