Heart failure is the inability of the heart to pump enough blood to meet the needs of the body’s organs. The function of the heart is to pump blood to keep blood circulating. The left side of the heart takes oxygen-rich blood and pushes it out to the body. The right side of the heart takes in oxygen-poor blood from the body and pushes it to the lungs where it gets filled with oxygen. If either side of the heart fails to work as it should, you can develop heart failure. ⠀ ⠀ Causes Any condition that weakens the heart muscle can cause heart failure. Inadequate supply of blood to the heart muscle because of atherosclerosis is one common cause. So it is a heart attack because it kills part of the heart muscle. Untreated high blood pressure can force the heart to work too hard and weaken it. Viral infections can weaken the heart muscle. So can certain diseases that lead to toxic substances being deposited in the heart. Leaky or blocked heart valves can also lead to heart failure. Too m...