The main cause of fluid overload is heart failure (also called congestive heart failure), a condition in which the heart is weakened and can't circulate enough blood to the body's other organs. When the flow of blood out of the heart slows, fluid builds-up in the body's tissues and the kidneys aren't able to get rid of the excess sodium (salt) and water.
Excess fluid can build up in various locations in the body, leading to swelling in the feet, ankles and lower legs (peripheral edema) and/or swelling in the abdomen (ascites). When excess fluid collects in the lungs, the condition is called pulmonary edema.
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.
According to the National Institutes of Health, almost 5 million people in the United States have heart failure, the foremost cause of fluid overload. Each year, about 550,000 new cases of heart failure are diagnosed. While the condition can develop in people of all ages, heart failure is more common among the elderly. Medicare data shows that heart failure is the most common diagnosis among elderly people who are hospitalized. And because the American population is aging, the number of people diagnosed with heart failure is increasing every year. Heart failure is also more common among people who are overweight or obese. Excess weight puts a greater strain on the heart. It also can lead to type 2 diabetes, which adds to the risk of heart failure.
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