What Causes Congestive Heart Failure?

According to the American Heart Association, all of us lose some blood-pumping ability in our hearts as we age. But the more serious loss that we call heart failure results from the added stress of health conditions that either damage the heart or make it work too hard. In fact, all of the behaviors that you probably associate with heart disease or heart attack — such as having high blood pressure, smoking, being overweight, eating foods high in fat and cholesterol, not exercising and having diabetes — can also cause heart failure. In some cases, though, behavior has absolutely nothing to do with heart failure. For instance, some people who develop heart failure were born with structural heart defects, while in others a virus damaged the heart muscle.

If you have heart failure, chances are you have (or had) one or more of the following. Some of these can be present without you knowing it.

Coronary artery disease
When cholesterol and fatty deposits build up in the heart's arteries, less blood reaches the heart muscle. This damages the muscle, and the healthy heart tissue that remains has to work harder.

Past heart attacks (myocardial infarction)
A heart attack occurs when an artery that supplies blood to the heart gets blocked. The loss of oxygen and nutrients damages the heart's muscle tissue — part of it essentially "dies." The remaining healthy tissue has to pump even harder to keep up.

High blood pressure (hypertension)
Uncontrolled high blood pressure increases a person's risk of developing heart failure by two to three times. When pressure in the blood vessels is too high, the heart has to pump harder than normal to keep the blood circulating. This takes a toll on the heart, and over time the chambers get larger and weaker.

Abnormal heart valves
Heart valve problems can result from disease, infection (endocarditis) or a defect present at birth. When the valves don't open or close completely during each heartbeat, the heart muscle has to pump harder to keep the blood moving. If the workload becomes too great, heart failure results.

Heart muscle disease (cardiomyopathy) or inflammation (myocarditis)
Any damage to the heart muscle — whether because of drug or alcohol use, viral infections or unknown reasons — increases the risk of heart failure.

Heart defects present at birth (congenital heart disease)
If the heart and its chambers don't form correctly, the healthy parts have to work harder to make up for it.

Severe lung disease
When the lungs don't work properly, the heart has to work harder to get available oxygen to the rest of the body.

Diabetes
Diabetes puts extra strain on the heart, increasing risk for heart failure. People with diabetes also tend to be overweight and have high blood pressure and high cholesterol — all of which make the heart work harder.

Typically these conditions cause the "wear and tear" that leads to heart failure. A combination of any of the above factors dramatically increases risk.

Less commonly, an otherwise healthy heart may become temporarily unable to keep up with the body's needs. This can happen in people who have:

Low red blood cell count (severe anemia)
When there aren't enough red blood cells to carry oxygen, the heart tries to move the small number of cells at a faster heart rate. It can become overtaxed from the effort.

An overactive thyroid gland (hyperthyroidism)
This condition causes the body to work at a faster pace, and the heart can be overworked trying to keep up.

Abnormal heart rhythm (arrhythmia or dysrhythmia)
When the heart beats too fast, too slow or irregularly, it may not be able to pump enough blood to meet all the body's needs.

In these cases, the person may experience heart failure symptoms until the underlying problem is identified and treated.