Congestive heart failure, which is commonly called simply “heart failure,” is a condition that occurs when the heart becomes weak and unable to pump enough blood to the body. This forces the heart to overwork, leading to a process called “remodeling,” which over time enlarges and makes it even weaker.

The result is that blood backs up into the lungs and fluid builds up in the body, making the heart work even harder.

There are two types of heart failure that may require different treatments, so getting the correct diagnosis is important.

Diastolic heart failure occurs when the heart’s left ventricle (its main pumping station) becomes stiff and can’t pump out enough blood. In this case, while less blood is pumped, the heart’s pumping ability — called ejection fraction — is generally preserved.

Systolic heart failure occurs when the left ventricle becomes weak, usually because the heart has become enlarged. Because of this, the heart muscle can’t contract the way it should, and its ability to pump blood to the rest of the body is hampered. Systolic heart failure is generally more serious, and it occurs most often in men. Diastolic heart failure occurs more often in women.