Swollen Legs Can Be a Sign of Troubles

One of many possible effects of heat is ankle swelling. So I thought I’d revisit ankle swelling, an article that I wrote back in 2008.

Your feet swell. You go to the doctor and get some water pills. It’s as simple as that, right?

Wrong. There are many causes of peripheral edema — swelling due to fluid retention in the tissues of the feet, ankles, legs and sometimes all the way up to the abdomen.

Without some detective work to discover the underlying problem, it’s not possible to select the correct treatment.

The most common cause of edema is venous disease. Older leg veins often don’t work as well as they did when they were brand-new. Varicose veins, injuries and damage from previous blood clots can increase the oncotic pressure in the tiniest blood vessels of the legs, called capillaries. Fluid then leaks through the capillary walls into the surrounding tissues. Water pills don’t work very well to treat this kind of edema.

Better treatments include special compression stockings and leg elevation. Exercise helps because active leg muscles squeeze the capillaries and helps return blood to the heart rather than permitting it to pool and leak.

Mild edema caused by leg vein problems may be uncomfortable or cosmetically unattractive, but it usually doesn’t indicate any serious underlying condition. But if edema starts suddenly and affects only one leg, it’s important to rule out a blood clot (deep venous thrombosis). Blood clots aren’t always painful, but they’re potentially life threatening because a piece may break loose and travel to the lungs.

When swelling caused by venous disease is severe, it can damage the leg tissues sufficiently that the skin breaks down and becomes ulcerated or infected.

So if your doctor recommends that you keep your legs elevated to combat swelling, do it!

A host of medical conditions can lead to peripheral edema. These include cardiovascular problems (high blood pressure, coronary artery disease, abnormal heart rhythms), liver, disease (such as cirrhosis from any source) and kidney disease. Your doctor will also ask about symptoms of pulmonary edema or fluid in the lungs. These symptoms can include shortness of breath with activity or at rest, or difficulty breathing that occurs when lying flat. There may be associated chest pain.

After your doctor reviews your history, he or she will probably order some tests to help pin down the cause of the edema. A chest X-ray looks for heart enlargement and fluid in the lungs. An EKG provides information about heart rhythm and heart muscle size and function. Blood tests look for low protein levels, kidney and liver function, electrolyte balance and anemia.

The treatment depends on which underlying cause turns up. Water pills, or diuretics, do have a place in the treatment of pedal edema caused by heart failure or liver disease. Many people assume that everyone who takes a water pill must also eat extra bananas for potassium. In reality there are three classes of diuretics: thiazide, loop and potassium sparing. While the first two classes may indeed lower potassium, the effect varies among individuals and is influenced by other medical conditions and medications. The amount of potassium contained in a banana is approximately 10 milliequivalents (10 mEq). But many patients on loop and thiazide diuretics require 20 or 40 mEq of potassium per day. If you require the higher dose, would you really want to eat four bananas every single day?

Potassium sparing diuretics often raise potassium levels; extra potassium is potentially dangerous for patients taking these drugs.

So if your feet swell, don’t expect your doctor to simply hand out water pills. They will want to look for the reason for your symptoms and choose the most effective treatment based on the underlying cause.