A quick quiz: What bodily system includes the tonsils, adenoids, spleen, thymus and many, many vessels?
Answer: the lymphatic system.

The what?

Though poorly understood by the average healthy person, the lymphatic system is a key player in the human circulatory and immune systems. Most of us give it little thought unless something goes wrong — something like lymphedema. Lymphedema is a disease with many different causes. One of the most common ways to get lymphedema — in the U.S., at least — is as a side effect of cancer treatment. The most obvious symptom is swelling, caused by lymphatic fluid accumulating usually in an arm or leg, and sometimes also in the head, neck, abdomen and genitals. Lymphedema is progressive — it gets worse and worse with time, and there is no known cure. On the bright side, there are treatments that can make it easier to live with. The most promising of these is complete decongestive physiotherapy, or CDP.

The Lymphatic System
The vessels of the lymphatic system transport tissue fluid (lymph) from the tissue spaces through the lymph nodes and back into the circulation. If an area of tissue is infected, the lymph transports germs and tissue chemicals to the adjacent lymph nodes, which react by producing cells that are released into the circulation to fight the infection. When you have a sore throat and get swollen glands (lymph nodes) on the sides of your neck, this is a sign that the lymphatic system has been activated to fight the infection. When a cancer is present in the tissues, it can enter the lymphatic vessels and be carried to the lymph nodes. That is the reason that lymph nodes are often checked for the presence of cancer cells. Cancer that has spread to the adjacent lymph nodes requires more advanced treatment than cancer that has not spread.

More About Lymphedema
Lymphedema occurs when the capacity of the lymphatic system to remove tissue fluid is less than the quantity of fluid entering the tissues. The result is swelling of the tissue. There are two main types of lymphedema. Primary lymphedema occurs when the lymphatic system is underdeveloped from birth. It may be present at birth, but more commonly, it may not become manifest until later in life, usually in young adulthood. Secondary lymphedema occurs when the system is damaged from the outside, for example, by infection, injury, surgery or radiation. In the extremely overweight, lymphedema can occur when the system simply becomes overloaded.

When you have a sore throat and get swollen glands (lymph nodes) on the sides of your neck...the lymphatic system has been activated to fight the infection.

In much of the world, the most common cause of lymphedema is infestation and damage by the parasitic disease filariasis. Filariasis is a tropical illness that produces lymphedema by infecting lymph nodes and blocking lymphatics, usually in the legs, and producing, in severe cases, elephantiasis, or grotesque swelling and skin changes of the legs and genitalia. In the United States, filariasis is not a risk. The most common causes are lymph node surgery or radiation for cancer treatment, primary (congenital) lymphedema and the swelling associated with a circulatory problem called chronic venous insufficiency, which occurs in some people with varicose veins.

For all types of lymphedema, the vast majority of sufferers are women. Arm lymphedema, caused by breast cancer treatment is the most common type associated with cancer treatment, but therapy for other cancers, including uterine, cervical, prostate and malignant melanoma, can also cause lymphedema, particularly in the legs.

How the Disease Works
Because lymphedema in the U.S. is so often linked with cancer treatment, we should make two things clear. Lymphedema is not cancer. And it is rarely life-threatening. Unfortunately, for both of these reasons, lymphedema is sometimes not taken seriously by cancer specialists and other doctors.

While it may not be as dangerous as cancer, lymphedema is progressive and irreversible. Whether because of physical disability or the embarrassment caused by swollen limbs, it can severely limit the lives of those it affects. And while it is not fatal in itself, it does put sufferers at greater risk for infections such as cellulitis, lymphangitis and septicemia that are potentially deadly. A recent study found that lymphedema increased the odds for developing erysipelas, a dangerous type of streptococcus infection, in the lower extremities 70-fold. Some people with lymphedema suffer from a condition called lymphorrhea, in which lymphatic fluid leaks through blisters in the skin. Lymphedema can be psychologically stressful for cancer patients, by serving as a constant reminder of the disease long after surgical incisions have healed and hair has grown back.

Until recently, most lymphedema patients were told, "It's not serious. Live with it." Since then, a number of new treatments have been developed, but with mixed results. One of them is microsurgery, which involves connecting lymph vessels to veins. This often works for a time, but eventually the connections tend to scar over and become blocked. While this kind of microsurgery is still being attempted in a few centers in different parts of the world, no long-term solution to this problem has yet been found.

By far the best of the new treatments is CDP, or complete decongestive physiotherapy, or CDT: complete (or complex) decongestive treatment.

Another is the use of external pneumatic pumps to transfer lymphatic fluid. The problem here is that the minute the pump is stopped, fluid quickly flows back and reaccumulates in the limb. This is because the fluid is not directed out of the quadrant of the body where the lymphatic system is damaged. Some patients increase the pump pressure or duration of treatment, so that, in time, this treatment will damage the skin and underlying tissue.

By far the best of the new treatments is CDP, or complete decongestive physiotherapy, or CDT: complete (or complex) decongestive treatment. There are other variations on the name but the basic principles are the same. The treatment consists of manual lymph drainage by external massage, followed by compression bandaging to keep the swelling from reoccurring. Therapeutic exercises and meticulous skin care are also part of this program. CDP was brought to the U.S. in 1989 by Dr. Robert Lerner, formerly Chief of Surgery, Brooklyn Jewish Hospital, New York, from the Foeldi Clinic in Germany.

How Complete Decongestive Physiotherapy Works
The two key elements of the treatment, manual lymph drainage and compression bandaging, take advantage of the fact that the lymphatic system is made up of both deep drainage vessels, which drain the muscles and other deeper tissues, and superficial vessels, which operate near the skin. When the system is working properly, the superficial system drains toward the deep system, then into vessels that are strained through the lymph nodes, then into the larger vessels that empty into major veins. Lymph node surgery causes lymphedema by removing those larger vessels along with the lymph nodes, thereby blocking the flow of lymphatic fluid.

In CDP, a trained therapist, with a detailed understanding of the lymphatic system, massages the skin very gently in order to redirect the lymphatic flow through connecting vessels to other adjacent lymphatic systems that are normal. The next step is to bandage the limb with multilayered bandages to keep the swelling from returning. During the first, more intensive phase of the CDP treatment program, a patient would receive manual lymph drainage and bandaging once or twice a day for five days a week and remain bandaged between sessions. This would continue as long as one or two weeks for a very mild case, or for up to 12 weeks for a very severe case. As part of the intensive treatment program, patients are taught how to bandage themselves for the second or maintenance phase of the program. During maintenance, which is a lifetime commitment, patients bandage at night and wear a compression sleeve or stocking during the day.

CDP and Exercise
There is a particularly dense network of lymphatic vessels surrounding our muscles. This network is connected to the vessels that serve the skin. When exercise causes the muscles to contract, lymphatic vessels also contract and the lymph flows — and drains — faster. During CDP therapists teach patients a series of exercises that can be done with be bandages or compression garment on.

After treatment, we also encourage normal exercise and activity for patients with certain precautions. The best type of exercise for lymphedema patients is swimming and other water exercises because the water provides tissue counter pressure on the skin lymphatics and the muscular exercise helps the lymph to flow. "Dry land" exercise like walking, running, biking or weight lifting must be done with either bandages or the compression garment in place. This is because increased muscular activity could cause increased swelling unless there is pressure on the skin to move the lymph out of the limb.

CDP and Skin Care
Infection and lymphedema can be a deadly combination. Minor injuries to parts of the body with damaged lymphatic systems can turn into life-threatening infections. Some of these further damage the lymphatic vessels and organs, leading to even worse lymphedema.

In CDP, the skin of the affected limb is treated with low pH lotion that inhibits bacterial growth. Those with lymphedema of the arm are cautioned to use gloves for gardening, dishwashing or any activity that would expose them to cuts. Manicures and removal of the nail cuticles should be strictly avoided. Those with lymphedema of the leg(s) should not walk in bare feet. For all outdoor activities, the skin should be protected with liberal applications of sunscreen. Patients are instructed to be on the lookout for the first signs of infection and should be ready to start immediately on an antibiotic, which should be kept on hand at all times.

Caveat Emptor
Fortunately for lymphedema patients, CDP is becoming available in more and more places in the U.S. However, the quality of the treatment is not uniform. Not all therapists receive the same training and not all centers use the same program. The Lymphedema Association of North America, LANA, is working to develop standardized training and testing to improve quality. Consumers should listen to the description of treatment and compare it with the section, "How Complete Decongestive Physiotherapy Works," in this write-up. The proposed treatment should be very similar. In addition, if a consumer received treatment purported to be CDP and did not improve, it would be worth consulting another provider or facility.

Lymphedema is a chronic, incurable condition resulting from inadequate lymph drainage. It is usually found in an arm or a leg. It can develop on its own or be acquired, most frequently from cancer surgery. The safest and most effective treatment is a technique called CDP or complete (sometimes complex) decongestive physiotherapy (or therapy).

If you have been diagnosed with lymphedema — even if the condition is hardly noticeable — it might be a good idea to begin CDP as soon as possible because CDP works best when it is started early. CDP is not for everyone. It takes a very determined, motivated patient to use this treatment to its greatest advantage. Because CDP is relatively new to the United States, your doctor may or may not be familiar with it. If necessary, you should insist on a referral to someone who is.

For More Information
Lerner Lymphedema Services - lymphedema treatment centers and therapist training academy.

National Lymphedema Network - support groups, newsletter, information about treatment centers and training programs.