The most common causes are past heart attacks or high blood pressure, but heart muscle damage may also be caused by infections or toxins. The heart muscle may become stiff, so that blood cannot enter it easily. This can be caused by high blood pressure and some other changes, common in older age. The heart valves may be narrowed or leak. If the valves do not work properly, not enough blood may be pumped forwards or the blood may leak backwards.
Rheumatic fever is the most common cause.
Heart diseases may be present at birth. That can cause heart failure at any age in life. There are other causes. These are not common. The treatment of your heart disease is also a part of the treatment of your heart failure.