Edema is the medical term for swelling caused by a collection of fluid in the small spaces that surround the body's tissues and organs. Edema can occur nearly anywhere in the body. Some of the most common sites are:

• The lower legs or hands (also called peripheral edema)


• Abdomen (also called ascites)


• Chest (called pulmonary edema if in the lungs and pleural effusion if in the space surrounding the lungs)

Ascites and peripheral edema can be uncomfortable and can be a sign of a more serious condition. Pulmonary edema, which can be life-threatening, is a symptom of heart failure and is discussed in more detail separately. 

Symptoms of edema depend upon the cause but may include:

• Swelling or puffiness of the skin, causing it to appear stretched and shiny. This typically is worse in the areas of the body that are closest to the ground (because of gravity). Therefore, edema is generally the worst in the lower legs (called peripheral edema) after walking about, standing, sitting in a chair for a period of time, or at the end of the day. It accumulates in the lower back (called sacral edema) after being in bed for a long period. Pushing on the swollen area for a few seconds will leave a dimple in the skin.


• Increased size of the abdomen (with ascites).


• Shortness of breath (with edema in the chest).

CONDITIONS ASSOCIATED WITH EDEMA



A number of different problems can cause edema.

Chronic venous disease — A common cause of edema in the lower legs is chronic venous disease, a condition in which the veins in the legs cannot pump enough blood back up to the heart because the valves in the veins are damaged. This can lead to fluid collecting in the lower legs, thinning of the skin, and, in some cases, development of skin sores (ulcers) 

Edema can also develop as a result of a blood clot in the deep veins of the lower leg (called deep vein thrombosis [DVT]). In this case, the edema is mostly limited to the feet or ankles and usually affects only one side (the left or right); other conditions that cause edema usually cause swelling of both legs.

Pregnancy — Pregnant women retain extra fluid. Swelling commonly develops in the hands, feet, and face, especially near the end of a normal pregnancy. Swelling without other symptoms and findings is not usually a sign that a complication, such as preeclampsia (sometimes called toxemia), has developed. 

Monthly menstrual periods — Edema in women that occurs in a cyclic pattern (usually once per month) can be the result of hormonal changes related to the menstrual cycle. This type of edema is common but does not require treatment because it resolves on its own.

Drugs — Edema can be a side effect of a variety of medications, including some oral diabetes medications, high blood pressure medications, non-prescription pain relievers (such as ibuprofen), and estrogens.

Kidney disease — The edema of kidney disease can cause swelling in the lower legs and around the eyes. 

Heart failure — Heart failure, also called congestive heart failure, is due to a weakened heart, which impairs its pumping action. Heart failure can cause swelling in the legs and abdomen, as well as other symptoms. Heart failure can also cause fluid to accumulate in the lungs (pulmonary edema), causing shortness of breath. This can be a very dangerous condition requiring emergency treatment. 

Cirrhosis — Cirrhosis is scarring of the liver from various causes, which can obstruct blood flow through the liver. People with cirrhosis can develop pronounced swelling in the abdomen (ascites) or in the lower legs (peripheral edema). 

Travel — Sitting for prolonged periods, such as during air travel, can cause swelling in the lower legs. This is common and is not usually a sign of a problem. Table 1 provides tips to minimize leg swelling during travel 

If your leg(s) remain swollen or you develop leg pain hours or days after the flight, contact your healthcare provider. Continued swelling and pain can be signs of a blood clot (DVT). 

DIAGNOSING THE CAUSE OF EDEMA



If you develop new swelling in one or both of your legs, hands, in your abdomen, or around your eyes, you should call your healthcare provider to determine if you need to be evaluated. 

TREATMENT



Treatment of edema includes several components: treatment of the underlying cause (if possible), reducing the amount of salt (sodium) in your diet, and, in many cases, use of a medication called a diuretic to eliminate excess fluid. Using compression stockings and elevating the legs may also be recommended.

Not all types of edema require treatment. Edema related to pregnancy or menstrual cycles is not usually treated. Peripheral edema and ascites are usually treated slowly to minimize the side effects of rapid fluid loss (such as low blood pressure).

Reduce salt (sodium) in your diet — Sodium, which is found in table salt and processed foods, can worsen edema. Reducing the amount of salt you consume can help to reduce edema, especially if you also take a diuretic. Guidelines on how to reduce sodium are available separately. 

Diuretics — Diuretics are a type of medication that causes the kidneys to excrete more water and sodium, which can reduce edema. Diuretics must be used with care because removing too much fluid too quickly can lower the blood pressure, cause lightheadedness or fainting, and impair kidney function.

You may have to empty your bladder more frequently after taking a diuretic. However, other side effects are uncommon when diuretics are taken at the recommended dose.

Compression stockings — Leg edema can be prevented and treated with the use of compression stockings. Stockings are available in several heights, including knee-high, thigh-high, and pantyhose. Knee-high stockings are sufficient for most patients. Some stockings can cause skin irritation or pain, although proper measurement and fitting of the stockings can reduce the risk of discomfort. 

Effective compression stockings apply the greatest amount of pressure at the ankle and gradually decrease the pressure up the leg. These stockings are available with varying degrees of compression.

• Stockings with small amounts of compression can be purchased at pharmacies and surgical supply stores without a prescription.


• People with moderate to severe edema, those on their feet a lot, and those with ulcers usually require prescription stockings. A healthcare provider may take measurements for stockings or may write a prescription for stockings and then have a surgical supply or specialty store take the necessary measurements.


• The white "antiembolism" stockings commonly given in the hospital do not apply enough pressure at the ankle and are not adequate treatment for edema.

Body positioning — Leg, ankle, and foot edema can be improved by elevating the legs above heart level for 30 minutes three or four times per day. Elevating the legs may be sufficient to reduce or eliminate edema for people with mild venous disease but does not usually suffice in more severe cases. In addition, it may not be practical for those who work to elevate their legs several times per day.