Heart failure is a condition in which the heart is no longer able to pump out enough oxygen-rich blood. This causes symptoms to occur throughout the body.
Heart failure is often a long-term (chronic) condition, but it may come on suddenly. It can be caused by many different heart problems.
Heart failure is present when the heart muscle cannot pump (eject) the blood out of the heart very well. This is called systolic heart failure. In other cases the heart muscles are stiff and do not fill up with blood easily. This is called diastolic heart failure.
As the heart's pumping becomes less effective, blood may back up in other areas of the body. Fluid may build up in the lungs, liver, gastrointestinal tract, and the arms and legs. This is called congestive heart failure.