Heart failure is a condition in which the heart cannot pump efficiently enough to meet the body's need for blood. Contrary to its name, heart failure does not mean the heart has failed completely. Heart failure is also called congestive heart failure.
The inefficient pumping associated with heart failure causes a backup of blood in the veins leading to the heart. It causes the kidneys to retain fluid. As a result, the body's tissues swell.
The swelling most commonly affects the legs. But it also can occur in other tissues and organs. When it occurs in the lungs, it causes breathing difficulty.
Heart failure often is the end stage of another form of heart disease. Its many causes include:
Coronary artery disease
High blood pressure (hypertension)
Heart valve disorders (including rheumatic heart disease)
Congenital heart disorders
Cardiomyopathy (disease of the heart muscle)
Cardiac arrhythmias (problems with the heart rate and/or rhythm)
Exposure to toxins, including excessive alcohol
Hyperthyroidism, diabetes and prolonged lung disease also increase the risk of heart failure.
In some people with heart failure, the heart muscle becomes weaker. It cannot pump as well. In other people, the heart muscle becomes stiff. As a result, the heart cannot fill with enough blood between heartbeats.