Heart failure happens when your heart doesn't pump as well as it should. Heart failure doesn't mean your heart is actually going to stop. A normal healthy heart pumps enough oxygen-rich blood to meet your body's oxygen needs. If your heart can’t squeeze or relax properly, it won't be able to pump enough blood. When this happens, symptoms of heart failure occur. There are two types of heart failure:
Systolic Heart Failure — In this type, a weak heart muscle doesn't squeeze as well as it should.
Diastolic Heart Failure — In this type, the heart can't fill with enough blood. This happens when the muscle has thickened or lost its ability to relax.
With both types of failure, blood can “back up” into your lungs and other parts of your body, including your hands, abdomen (belly), legs and feet. This fluid back up is sometimes called "congestion” or congestive heart failure. Congestion often causes heart failure symptoms. If you have moderate to severe systolic heart failure, you may have symptoms without congestion.