heart failure is caused by many conditions that damage the heart muscle including: coronary artery disease: cad a disease of the arteries that supply blood and oxygen to the heart causes decreased blood flow to the heart muscle. if the arteries become blocked the heart becomes starved for oxygen and nutrients. this condition along with heart attack is responsible for two thirds of heart failure cases in the u. s. heart attack: a heart attack may occur when a coronary artery becomes suddenly blocked stopping the flow of blood to the heart muscle and damaging it. all or part of the heart muscle becomes cut off from its supply of oxygen. a heart attack can damage the heart muscle resulting in a scarred area that does not function properly. "non-ischemic" cardiomyopathy: this condition occurs when there is damage to the heart muscle from causes other than artery or blood flow problems such as from infections or alcohol or drug abuse. conditions that overwork the heart: high blood pressure (hypertension) valve disease thyroid disease kidney disease diabetes or heart defects present at birth can all cause heart failure (some of these are non-ischemic cardiomyopathy -- see above). in addition heart failure can occur when several diseases or conditions are present at once.
what causes heart failure?