DO YOU HAVE PUFFY LEGS?

Edema is swelling or puffiness of parts of the body. Edema typically occurs in the feet or legs, in which case it is referred to as peripheral edema. The swelling is caused by fluid that gets trapped in the tissues of the body–outside of the blood vessels. These spaces are known as interstitial spaces.

Most edema is pitting edema, which can be demonstrated by applying pressure to the skin overlying the edema. If your finger leaves an indentation, this is pitting edema. Even the elastic band at the top of a sock can demonstrate pitting edema by leaving a dent. In nonpitting edema, pressure applied to the skin does not leave an indentation. This is usually caused by disorders of the lymphatic system such as that may occur after a radical mastectomy or in lymphedema. Nonpitting edema does not respond to the same treatments used for pitting edema and is usually treated by elevating the legs during the day, and applying compression stockings or wraps, which are similar to bandages. The rest of this article will focus on pitting edema.

Edema is caused by diseases affecting various organs of the body – the heart, liver, or kidney – or by local conditions affecting only the legs. With systemic diseases causing edema, edema occurs because of excess salt retention. Salt (or sodium chloride) acts as a magnet for water and pulls water into the interstitial spaces, causing peripheral edema. Diseases in the legs can also cause edema. The most common conditions are varicose veins and thrombophlebitis (a disease caused by inflammation of the veins, usually after a blood clot). These local diseases may cause asymmetrical edema in which the swelling is greater in one leg than the other. Finally, idiopathic edema is a condition which primarily affects young, pre-menopausal women and typically occurs before each menstrual period. Peripheral edema can also be caused by sunburn, pregnancy, and standing or walking a lot when the weather is warm. Many drugs can cause edema – typically by increasing the amount of salt that the kidney reabsorbs from the urine. These drugs include minoxidil, diazoxide, nifedipine (Procardia/Adalat), amlodipine (Norvasc), felodipine (Plendil), NSAIDs like ibuprofen (Motrin) and naproxyn (Aleve), and estrogens in hormone replacement or oral contraceptive pills.

Edema is most often treated by strong diuretics (also called water pills) like Lasix (furosemide) or Bumex (bumetanide). Hydrochlorothiazide is a diuretic that is commonly used to treat high blood pressure but, by itself, is not strong enough to treat most cases of peripheral edema. Diuretics cause the kidney to excrete more salt and water through urination – pulling the excess fluid out of the interstitial spaces and reducing the edema. These diuretics are most effective in edema caused by systemic diseases. In idiopathic edema, taking diuretics may actually worsen the edema by producing a rebound phenomenon whenever the patient tries to stop the diuretics. Diuretics may also be ineffective for edema caused by varicose veins and thrombophlebitis. These conditions often require treatment with compression stockings and even surgery. Restricting salt intake is also important in decreasing peripheral edema. Many people cut down on salt intake by avoiding sprinkling salt on their food from the salt shaker but it is important to remember that most packaged food – canned food, frozen dinners, restaurant food – also are high in salt and should be avoided.

Dr. McMahon, a graduate of Yale University and the University of Pittsburgh School of Medicine, is board certified in Internal Medicine. She is a member of the American College of Physicians and the Allegheny County and Pennsylvania Medical Societies. She is in solo practice in the North Hills of Pittsburgh.