The human body is approximately 60 percent water, which is essential to almost every life process. But sometimes a condition called fluid overload can occur, in which more fluid (primarily water) is going into your body than is coming out.
The chief cause of fluid overload is heart failure, a condition in which the heart muscle loses its ability to pump adequately. As the heart's contractions (beats) become weaker and less able to pump out the blood that enters the heart, blood backs up in the veins, causing fluid buildup in the body's tissues. The kidneys' ability to eliminate excess sodium and water is also affected by heart failure, further increasing the body's fluid congestion.
Fluid overload can also occur as a result of some other health conditions, including kidney disease and liver disease. It can also be a side effect of some medications.
Excess fluid can build up in various locations in your body, leading to a condition called edema. Edema is swelling that usually occurs in the feet, ankles and legs (where it's called peripheral edema), but it also can occur in the lungs (where it's called pulmonary edema) and in the abdomen (where it's called ascites).
Fluid buildup can also cause increasing fatigue. You may begin to feel tired after performing normal daily activities or walking even a short distance. When fluid overload is not too severe, it can be treated with a program of diet and lifestyle changes.
Heart failure occurs predominately in the elderly, but it can affect people of any age. Not surprisingly, since the number of older Americans is growing, the number of heart failure diagnoses each year is increasing at almost 10 percent.
Heart failure can be characterized by the side of the heart that's weakened -- based on that, patients can develop edema in different places in their bodies. When the right side of the heart is weakened, oxygen-poor blood tends to back up in the veins. As a result, fluid buildup tends to occur in the lower body (legs and feet), and sometimes in the abdomen. When the left side of the heart is weakened, oxygen-rich blood tends to back up in the lungs, resulting in fluid buildup there.
On the next page, we'll learn about the symptoms of edema.
Symptoms of Edema
In years gone by, when someone's lower legs, ankles and feet were swollen, people called it "dropsy." Today, however, we call it edema. It's important to note that edema isn't a disease but the symptom of an underlying condition, like fluid overload or heart failure (in which the heart is not pumping well enough to meet the body's demand for oxygen).
Edema usually begins with leakage of fluid from the tiniest blood vessels into nearby tissues. When the body senses that fluid is being lost from these vessels, it signals the kidneys to hold on to more fluid, increasing the volume of fluid in the vessels and leading to additional leakage.
Edema can occur if you sit or stand in one place for too long, as gravity pulls water down into your legs and feet. The veins in your legs have small valves that help keep blood from running down toward your feet between heartbeats. If these valves are not functioning properly, edema can develop in the legs. Pregnant women sometimes get edema, and people who eat a diet too high in sodium (salt) can also develop it. Certain conditions, such as kidney or liver disease, can also cause edema or make it worse
Signs that you might have edema include:
- Stretched and shiny-looking skin over a swollen area
- Increased abdomen size (ascites)
- Shortness of breath or difficulty breathing (pulmonary edema)
- Tightness of jewelry, clothing or accessories
- Low output of urine, even when you're drinking as much fluid as normal
- A dimple in the skin covering the swollen area that remains for a few seconds after a pressing finger has been released
Symptoms of more serious edema (such as pulmonary edema) include:
- Difficulty breathing
- Shortness of breath when lying down
- Cold hands or feet
On the next page we'll find out about treatments for fluid overload and edema.
Fluid Overload and Edema Diagnosis and Treatment
Your doctor will obtain a detailed medical history and conduct a full exam. He or she will listen to your lungs through a stethoscope to detect the presence of fluid (an indication of pulmonary edema) and look at the veins in your neck.
Your doctor might order tests to help make a diagnosis. Results of blood and urine tests are useful for the diagnosis of certain types of fluid overload related to kidney or liver disease. Your doctor may order tests to detect abnormalities in your heart's electrical activity, size, shape and function during rest and exercise.
If you have fluid overload, your doctor will probably suggest that you reduce the amount of sodium (salt) in your diet. Doing so can be a very effective way of combating the buildup of excess fluid. Most Americans eat a diet containing lots of processed foods, which are very high in sodium.
Leg, ankle and foot edema can be improved if you elevate your legs above the level of your heart for 30 minutes three or four times each day. Compression or support stockings can also help edema.
Your doctor may prescribe oral medicines (diuretics or "water pills") to reduce the symptoms of the condition. Diuretics cause the kidneys to pass more water and sodium, reducing fluid volume throughout the body. Unfortunately, these medications often become less effective the longer one takes them, and eventually many people with fluid overload require hospitalization.
Typically, an in-hospital treatment for a serious case of edema includes intravenous (given with a needle into the bloodstream) administration of medications such as diuretic drugs, vasodilator drugs and inotropic drugs.
If intravenous drug therapy doesn't relieve the edema, patients may receive a procedure known as ultrafiltration, which uses a filtering device to remove excess fluid.
Follow the links on the next page to learn more about fluid overload and edema.
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More Great Links
- Costanzo MR, Guglin ME, Saltzberg MT, et al. Ultrafiltration versus intravenous diuretics for patients hospitalized for acute decompensated heart failure. J Am Coll Cardiol. 2007; 49:675-683.
- Costanzo MR, Saltzberg M, O'Sullivan J. Early ultrafiltration in patients with decompensated heart failure and diuretic resistance. J Am Coll Cardiol. 2005;46:2047-2051.
- Elkayam U, Hatamizadeh P, Janmohamed M. The challenge of correcting volume overload in hospitalized patients with decompensated heart failure. J Am Coll Cardiol. 2007;49:684-686.