By: MSF Staff and reviewed by the MSF Medical Advisory Board
Swollen feet and ankles are common in MS, and are caused by an accumulation of lymphatic fluid (lymphedema). They are considered to be a secondary symptom of the disease, because they most often develop due to a lack of mobility instead of arising as a direct result of demyelination.
How This Happens
Lymphatic fluid delivers nutrients and other substances to and from organs in the body. Normally, the contractions of active leg muscles move this fluid along in lymphatic channels, propelling it upward towards the body cavity. When the body becomes less mobile, as may happen with MS, the kneading action does not occur, the fluid leaks from the channels and accumulates by gravity in the ankles and feet.
What You May Experience
Lymphedema is usually painless. There may be a tight feeling in the skin, and it may thicken and become fibrous. Swelling may make it difficult to wear shoes and further hinder mobility, interfering with daily activities. Rising summertime temperatures may exacerbate the problem, since blood vessels and lymph channels dilate more in the heat.
Ruling Out Other Causes
Lymphedema can also occur because the heart is not functioning properly. In this instance, the swelling may be accompanied by shortness of breath, coughing, and a feeling of not being well. Another condition that can cause swelling is thrombophlebitis, or inflammation of the veins. With this condition, swelling happens rapidly, especially in one leg, and is accompanied by redness and pain. Your physician will assess your particular situation to determine the cause of your swelling and rule out these and other possible causes.
Treatment is Important
Getting rid of the excess liquid is important, as complications can develop when the condition is not treated: tissue channels increase in size and number, less oxygen exists in the transport system, wound healing may be hindered, and a bacteria-friendly environment could lead to inflammation of the lymph vessels.
Too often doctors treat lymphedema with diuretics, which does not solve the problem. Though they may work initially, the fluid returns because the fluid mobilized with the diuretic is intravascular fluid; thus, a person can become “dehydrated” with excess fluid in their extremities.
Elevating the legs helps by pushing the fluid back into the body and allowing more area for it to be absorbed. The affected leg or legs should be placed higher than the hips.
A compression pump system can assist in pushing the fluid back up into the body. A fitted sleeve is placed over the affected area and fastened with Velcro. When the pump is activated, high pressure compression moves through several different compartments, giving a natural kneading process to the muscles. This allows the fluid to get back into circulation and be carried away.
When the pump is not being used, a graduated compression stocking should be worn. Massage can also be effective but is time consuming and not practical on a long-term basis. In addition, physical exercise has been shown to offer relief, though since mobility is often a factor this can be difficult. If the skin is still intact, practicing water aerobics is a good and effective alternative.
Anyone who experiences swollen ankles and feet should contact his or her physician so that the condition can be diagnosed and the proper treatment can be prescribed.
(Last reviewed 2/2013)