Edema (Fluid accumulation in soft tissues)

Edema can be caused by several problems. Edema can occur in the legs as a result of problems like kidney failure, liver failure, blood clots in the veins in the legs, and local infections in the legs. Sometimes mild swelling in the feet and ankles is related to nothing more than sitting in a chair for a long time, such as in an airline seat during a long flight. It can also be caused by having your legs crossed for extended periods.

If edema involves the lungs, it is usually due to heart failure. The lungs become swollen or edematous, and this is typically what causes the shortness of breath associated with heart failure.

Edema caused by heart failure  may first show itself in swollen feet and ankles. The usual treatment is diuretic drugs, which will cause you to eliminate fluid through your kidneys. Heart failure may also be treated with drugs that dilate the vessels, or with a drug like digitalis (also called digoxin or Lanoxin), which has a number of effects but is also believed to cause the heart to contract more vigorously and thereby relieve the heart failure to some degree, thus relieving the swelling also.

Edema sometimes becomes generalized over your body, a condition called Anasarca. This swelling extends throughout the body but affects the legs and abdomen more than the chest and the face. It can be caused by severe heart failure. It can also be caused by other problems such as liver failure or kidney failure, and in severe forms of anasarca, one may accumulate extra fluid inside the abdominal cavity, which is called ascites.

Edema, anasarca, and ascites, when caused by heart failure, result because the failing heart is no longer able to pump the appropriate amount of blood. As a result, the blood backs up, blood pressure rises in the lungs, and blood is pushed further backwards to the liver and other abdominal organs. This causes the fluid in the blood to leak out through the blood vessels into the tissues.

Edema can occur in some parts of the body and spare other parts. If you a have a saphenous vein graft taken from one leg to be used in bypass surgery, swelling of this leg can occur after the operation while the other leg will look normal. The saphenous vein is responsible for taking blood from your leg back to a big groin (femoral) vein and then back to the heart. When it is removed, some fluid pools into your leg causing swelling. This will take sometime and will then resolve. Another example is a disease called superior vena cava obstruction. In this condition, the superior vena cava ( big vein draining the upper half of the body) is obstructed with a thrombus. This will result in swelling of the upper half of your body, while the lower half will look normal. 

Symptoms:

Edema itself doesn't cause severe symptoms. Some patients describe the feeling of tension and numbness in the swollen area of their body. Usually there is accompanying symptoms of the cause of this edema. For example, if a patient has heart failure, he might also complain of shortness of breath or palpitations besides his swelling. A patient with liver problem might complain of yellowish color of his eyes and increased tendency for bleeding.

Examination

When your doctor examines you, he will be looking for a cause of this edema. He might find redness and pain in the affected area which can suggest an infection. The presence of a murmur over you heart and crackle sounds over your lungs may suggest heart failure. There are important signs which can occur with edema and signify a major problem:

1. Sudden shortness of breath.
2. Severe pain and swelling of one leg.
3. Abdominal collection of fluid (ascitis) together with enlarged liver.
4. Coughing of blood .

Diagnostic tests:

Blood tests are done to help find a diagnosis. A complete blood count together with kidney functions and liver functions are usually ordered. Protein in urine is measured to see if the kidneys are the cause of such edema. If your physician suspects a problem with your heart, he will request an echocardiogram .

Treatment:

Treatment is usually directed toward the underlying cause. For example, If heart failure is the cause, diuretics, cardiac glycosides and ACE inhibitors might be prescribed.