What Is It?

Edema is swelling of both legs from an accumulation of excess fluid. Edema has many possible causes:

  • Prolonged standing or sitting, especially in hot weather, can cause excess fluid to accumulate in the feet, ankles and lower legs.
  • Venous insufficiency is a common problem caused by weakened valves in the veins of the legs. This makes it more difficult for the veins to pump blood back to the heart, and leads to varicose veins and buildup of fluid.
  • Severe chronic lung diseases, including emphysema and chronic bronchitis, increase the pressure in the blood vessels that lead from the heart to the lungs. This pressure backs up in the right side of the heart and the higher pressure causes swelling in the legs and feet.
  • Congestive heart failure, a condition in which the heart can no longer pump efficiently, causes fluid buildup in the lungs and other parts of the body. The swelling is often most visible in the feet and ankles.
  • Edema in the legs can occur during pregnancy because the pregnant uterus puts pressure on the vena cava, a major blood vessel that returns blood to the heart from the legs. Fluid retention during pregnancy also can be caused by a more serious condition called preeclampsia.
  • Low protein levels in the blood that can be seen in malnutrition, kidney and liver disease can cause edema. The proteins in the blood help to hold salt and water inside the blood vessels so fluid does not leak out into the tissues. If the most abundant blood protein, called albumin, gets too low, fluid is retained and edema occurs, especially in the feet, ankles and lower legs.


Symptoms vary according to the type of edema and its location. In general, skin covering the swollen area will be stretched and shiny.


To check for edema that is not obvious, you can gently press your thumb over the foot, ankle or leg with slow, steady pressure. If edema is present, an indentation will show on the skin. You should see a doctor to determine the cause of leg swelling. If both legs are swollen, your doctor will ask about other symptoms and do a physical examination. A urine test will show if you are losing protein from the kidneys. Blood tests, a chest X-ray and an electrocardiogram (EKG) also may be ordered.

Expected Duration

Edema can be temporary or permanent. Also, it can come and go depending on the cause.


The only way to prevent edema is to prevent the cause. Smoking is the main cause of chronic lung disease. Congestive heart failure most often is caused by coronary artery disease, high blood pressure, or excessive alcohol use. To avoid leg swelling on long trips, stand up and walk around often. Ideally, you should get up once an hour. If that’s not possible, then exercise your feet and lower legs while sitting. This will help the veins move blood back toward the heart.


Treatment of edema focuses on correcting the underlying cause of the fluid accumulation. In addition, a low-salt diet and avoiding excess fluid intake usually helps. If you are not short of breath, elevating your legs above the level of your heart also will keep swelling down. Your doctor might suggest that you take a low dose of a diuretic (water pill).

For swollen ankles and feet caused by pregnancy, you can elevate your legs and avoid lying on your back to help improve blood flow and decrease swelling.

If your have mild leg edema caused by venous insufficiency, you can elevate your legs periodically and wear support (compression) stockings. Sometimes surgery is needed to improve the flow of blood through the leg veins.

No matter what the cause of edema, any swollen area of the body should be protected from pressure, injury and extreme temperatures. The skin over swollen legs becomes more fragile over time. Cuts, scrapes and burns in areas that have edema take much longer to heal and are more prone to infection.

When To Call A Professional

Call your doctor immediately if you have pain, redness or heat in a swollen area, an open sore, shortness of breath or swelling of only one limb.


The prognosis for edema of the legs depends on the cause. For most people with edema, the prognosis is excellent.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

  A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.