Heart Failure

What is heart failure?

Heart failure is the inability of the heart to fill with or pump out enough blood to meet the body's needs.1 Heart failure doesn't mean that your heart has stopped or is about to stop working, just that it has become an inefficient pump.

Heart failure is not one single disease, but rather a group of signs and symptoms caused by many different disease processes that have weakened the heart over time and left it unable to pump blood efficiently. Heart failure can take different forms in different people. For some, heart failure may involve a blood-pumping problem (systolic heart failure); for others, it may be a blood-filling problem (diastolic heart failure). Heart failure may affect only one side of the heart—the left or the right—or both sides at the same time. See our section on the different forms of heart failure for more information on left-sided and right-sided heart failure.

Heart failure is sometimes referred to as congestive heart failure, but this is misleading because the buildup of fluid (congestion) in the lungs and other parts of the body doesn't occur in everyone. Heart failure is also called chronic heart failure because the condition usually develops gradually over a long period of time.

What are the symptoms of heart failure?

The most common symptoms of heart failure are shortness of breath while active or lying down, fatigue, persistent coughing, and swelling of the ankles, feet, legs and sometimes the belly.1 Fatigue is the most common sign of heart failure in elderly people, which may be why it often takes a long time for them to be diagnosed. The symptoms are generally the same whether you have systolic heart failure or diastolic heart failure. Women are more likely than men to have shortness of breath (67% to 63%) and swollen ankles (29% to 22%).2

Symptoms can be mild to severe, and they can come on suddenly or begin gradually and worsen over time. Mild symptoms, such as shortness of breath with activity, are often mistaken for signs of aging. For this reason, many women are unaware of their condition until years after their heart begins to deteriorate. Some people in the early stages of heart failure don't even have any symptoms.

The symptoms of heart failure are common in other conditions, such as asthma and lung disease. If you have symptoms such as shortness of breath and persistent cough, your doctor will do a thorough medical history and physical examination and order blood and imaging tests to rule out other possible causes for these symptoms and to check on your heart's pumping capacity.

See our section on the signs and symptoms of heart failure for more detailed information.

What happens to the heart during heart failure?

Conditions that can lead to heart failure, such as high blood pressure and coronary artery disease, share the common feature of making the heart work harder to pump blood to the body. To make up for the added strain, the heart compensates by changing its shape in different ways. The pumping chambers (the ventricles) can stretch (dilate) to hold more blood for pumping. The chambers can also develop a thicker muscle wall ( hypertrophy) that allows them to pump blood with more force, increasing the amount of blood pumped to the body.

These "compensatory" changes can go on for many years without impairing the heart's ability to function. This is why you may not have any symptoms when your heart first begins to fail, because the heart is compensating for its gradual decline in performance. Eventually, however, the heart can no longer compensate and begins to weaken. In those who develop an enlarged (dilated) heart, the walls of the heart become over-stretched and too weak to pump blood efficiently anymore. In the case of hearts with thickened (hypertrophied) muscle, the walls become too thick and stiff to relax and allow the heart to fill with enough blood, resulting in less blood available for pumping. No matter what the cause (dilated or hypertrophied hearts), blood begins to back up and build up in the lungs, arms, legs, and ankles. At this stage of heart failure, you notice symptoms such as shortness of breath, fatigue, and swelling. From here on, the disease can progress and the symptoms worsen, but they may stabilize and improve with the proper treatment.

How common is heart failure?

Approximately 5 million Americans are currently living with heart failure, half of them women. In 2004, heart failure contributed to approximately 285,000 deaths; close to 60% were women. From age 40, the average woman or man has a 1 in 5 (20%) chance of developing heart failure at some point in their life.4 African-American women have a 50% to 60% higher risk than women of other races.3

American Heart Association's Heart Disease & Stroke Statistics3
2005 Heart Failure Prevalence By Race
African-American White Mexican-American
Women 3.3% 2.1% 1.9%
Men 2.7% 2.8% 2.1%
Adults 20 years of age or older


Heart failure can happen to anyone. Until age 80, heart failure is more common in men than in women. After age 80, heart failure begins to occur more frequently in women than in men, largely because more women than men live beyond the age of 80.1

Heart Failure Prevalence By Sex & Age 1999-2004 Bar Graph

Next: Stages and Classification of Heart Failure

Filed in Cardiovascular Disease > Featured