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What Is Heart Failure?


Heart failure is a serious but common condition. In heart failure, the heart cannot pump enough blood to meet the body's needs. Heart failure develops over time as the pumping action of the heart gets weaker, or if it gets more difficult to adequately fill the heart with blood between heartbeats. It can affect either the right, the left, or both sides of the heart. Heart failure does not mean that the heart has stopped working or is about to stop working.

An older woman with swollen feet puts on her shoes.When heart failure affects the left side of the heart, the heart cannot pump enough oxygen-rich blood to the rest of the body. When heart failure affects the right side of the heart, the heart cannot pump enough blood to the lungs, where it picks up oxygen. When the heart is weakened by heart failure, fluid can back up into the lungs, and fluid builds up in the feet, ankles, and legs. People with heart failure often experience tiredness and shortness of breath.

Learn more about The Heart Truth®, a national heart disease awareness campaign for women from the National Heart, Lung, and Blood Institute.

In people over age 65, heart failure is also caused by a thickened and stiff heart muscle that relaxes too slowly, causing fluid to back up into the lungs when the heart is stressed, such as during physical activity. Long-term hypertension and obesity are risk factors for this type of heart failure. Symptoms include shortness of breath when active, at rest, and while lying flat, as well as swelling in the legs and feet. Although the heart muscle is not damaged or weak in this type of heart failure, it can be a very debilitating condition if not treated.

Heart failure is caused by other diseases or conditions that damage the heart muscle, such as coronary heart disease, heart attacks, diabetes, and high blood pressure. Treating these problems before the heart muscle is damaged can prevent heart failure.

To learn more about heart failure, visit the National Heart, Lung, and Blood Institute.

For More Information About Heart Failure

American Heart Association

National Heart, Lung, and Blood Institute

National Library of Medicine

This content is provided by the NIH National Institute on Aging (NIA). NIA scientists and other experts review this content to ensure it is accurate and up to date.

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