Heart Failure - Heart failure causes - Congestive heart failure

Heart Failure

Heart failure is a serious long-term condition, but you can live a full and enjoyable life with the right treatment and active attention to your lifestyle.

The most important thing to remember is that you're not alone. An estimated 5.7 million Americans are living with heart failure, and 670,000 new cases are diagnosed each year. You can manage this condition, and we’re here to help. Regardless of your treatment, you need to follow all of your doctor’s recommendations and make the necessary changes in diet, exercise and lifestyle to give you the highest possible quality of life.

What is Heart Failure

How the normal heart works
What is heart failure?
Left-sided heart failure
Right-sided heart failure
Congestive heart failure

How the normal heart works
The normal heart is a strong, muscular pump a little larger than a fist. It pumps blood continuously through the circulatory system.

The heart has four chambers, two on the right and two on the left:

Two upper chambers called atria (one is an atrium)
Two lower chambers called ventricles

Oxygen-rich blood travels from the lungs to the left atrium, then on to the left ventricle, which pumps it to the rest of the body.

The right atria takes in oxygen-depleted blood from the rest of the body and sends it back out to the lungs throught the right ventricle.

The heart pumps blood to the lungs and to all the body's tissues by a sequence of highly organized contractions of the four chambers. For the heart to function properly, the four chambers must beat in an organized way.

Watch an animation of heart failure compared to the healthy heart

What is heart failure?

Heart failure is a chronic, progressive condition in which the heart muscle is unable to pump enough blood through the heart to meet the body’s needs for blood and oxygen. Basically, the heart can’t keep up with its workload.

At first the heart tries to make up for this by:

Enlarging. When the heart chamber enlarges, it stretches more and can contract more strongly, so it pumps more blood.
Developing more muscle mass. The increase in muscle mass occurs because the contracting cells of the heart get bigger. This lets the heart pump more strongly, at least initially.
Pumping faster. This helps to increase the heart's output.

The body also tries to compensate in other ways:

The blood vessels narrow to keep blood pressure up, trying to make up for the heart's loss of power.
The body diverts blood away from less important tissues and organs to maintain flow to the most vital organs, the heart and brain.

These temporary measures mask the problem of heart failure, but they don't solve it. Heart failure continues and worsens until these substitute processes no longer work.

Eventually the heart and body just can't keep up, and the person experiences the fatigue, breathing problems or other symptoms that usually prompt a trip to the doctor.

The body's compensation mechanisms help explain why some people may not become aware of their condition until years after their heart begins its decline. (It's also a good reason to have a regular checkup with your doctor.)

Heart failure can involve the heart's left side, right side or both sides. However, it usually affects the left side first.

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Left-sided heart failure

The heart's pumping action moves oxygen-rich blood travels from the lungs to the left atrium, then on to the left ventricle, which pumps it to the rest of the body. The left ventricle supplies most of the heart's pumping power, so it's larger than the other chambers and essential for normal function. In left-sided or left ventricular (LV) heart failure, the left side of the heart must work harder to pump the same amount of blood.

There are two types of left-sided heart failure. Drug treatments are different for the two types.

Systolic failure: The left ventricle loses its ability to contract normally. The heart can't pump with enough force to push enough blood into circulation.
Diastolic failure: The left ventricle loses its ability to relax normally (because the muscle has become stiff). The heart can't properly fill with blood during the resting period between each beat.

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Right-sided heart failure

The heart's pumping action moves "used" blood that returns to the heart through the veins through the right atrium into the right ventricle. The right ventricle then pumps the blood back out of the heart into the lungs to be replenished with oxygen.

Right-sided or right ventricular (RV) heart failure usually occurs as a result of left-sided failure. When the left ventricle fails, increased fluid pressure is, in effect, transferred back through the lungs, ultimately damaging the heart's right side. When the right side loses pumping power, blood backs up in the body's veins. This usually causes swelling in the legs and ankles.

Congestive heart failure is a type of heart failure which requires seeking timely medical attention, although sometimes the two terms are used interchangeably.

As blood flow out of the heart slows, blood returning to the heart through the veins backs up, causing congestion in the body's tissues. Often swelling (edema) results. Most often there's swelling in the legs and ankles, but it can happen in other parts of the body, too.

Sometimes fluid collects in the lungs and interferes with breathing, causing shortness of breath, especially when a person is lying down. This is called pulmonary edema and if left untreated can cause respiratory distress.

Heart failure also affects the kidneys' ability to dispose of sodium and water. This retained water also increases swelling in the body's tissues (edema).

Signs and Symptoms of Heart Failure

By themselves, the signs of heart failure may not be cause for alarm. But if you haven’t been diagnosed with heart failure and you have more than one of these symptoms, report them to a healthcare professional and ask for an evaluation of your heart.

If you have been diagnosed with heart failure, it's important for you to keep track of symptoms and report any sudden changes to your healthcare team.

This table lists the most common signs and symptoms, explains why they occur and describes how to recognize them.

Try our interactive heart failure signs and symptoms animation.

Sign or Symptom	Why It Happens	People with Heart Failure May Experience...
Shortness of breath (also called dyspnea)	Blood "backs up" in the pulmonary veins (the vessels that return blood from the lungs to the heart) because the heart can't keep up with the supply. This causes fluid to leak into the lungs.	. . . breathlessness during activity (most commonly), at rest, or while sleeping, which may come on suddenly and wake you up. You often have difficulty breathing while lying flat and may need to prop up the upper body and head on two pillows. You often complain of waking up tired or feeling anxious and restless.
Persistent coughing or wheezing	Fluid builds up in the lungs (see above).	. . . coughing that produces white or pink blood-tinged mucus.
Buildup of excess fluid in body tissues ( edema)	As blood flow out of the heart slows, blood returning to the heart through the veins backs up, causing fluid to build up in the tissues. The kidneys are less able to dispose of sodium and water, also causing fluid retention in the tissues.	. . . swelling in the feet, ankles, legs or abdomen or weight gain. You may find that your shoes feel tight.
Tiredness, fatigue	The heart can't pump enough blood to meet the needs of body tissues. The body diverts blood away from less vital organs, particularly muscles in the limbs, and sends it to the heart and brain.	. . . a tired feeling all the time and difficulty with everyday activities, such as shopping, climbing stairs, carrying groceries or walking.
Lack of appetite, nausea	The digestive system receives less blood, causing problems with digestion.	. . . a feeling of being full or sick to your stomach.
Confusion, impaired thinking	Changing levels of certain substances in the blood, such as sodium, can cause confusion.	. . . memory loss and feelings of disorientation. A caregiver or relative may notice this first.
Increased heart rate	To "make up for" the loss in pumping capacity, the heart beats faster.	. . . heart palpitations, which feel like your heart is racing or throbbing.

Causes of Heart Failure

All of us lose some blood-pumping ability in our hearts as we age, but heart failure results from the added stress of health conditions that either damage the heart or make it work too hard.

All of the lifestyle factors that increase your risk of heart attack and stroke – smoking, being overweight, eating foods high in fat and cholesterol and physical inactivity – can also contribute to heart failure.

If you have heart failure, chances are you have (or had) one or more of the conditions listed below. Some of these can be present without you knowing it. Typically these conditions cause the "wear and tear" that leads to heart failure. Having more than one of these factors dramatically increases your risk.

Coronary artery disease
Past heart attack (myocardial infarction)
High blood pressure (hypertension)
Abnormal heart valves
Heart muscle disease (dilated cardiomyopathy, hypertrophic cardiomyopathy) or inflammation (myocarditis)
Heart defects present at birth (congenital heart disease)
Severe lung disease
Diabetes
Other conditions

Coronary artery disease
When cholesterol and fatty deposits build up in the heart's arteries, less blood can reach the heart muscle. This build-up is known as atherosclerosis. The result may be chest pain (angina) or, if blood flow becomes totally obstructed, a heart attack. Coronary artery disease can also contribute to having high blood pressure which, over time, can also lead to heart failure.
Watch an animation of atherosclerosis
Watch an animation of coronary artery disease
Learn more about coronary artery disease at our Heart Attack Web site

Past heart attack (myocardial infarction)
A heart attack occurs when an artery that supplies blood to the heart muscle gets blocked. The loss of oxygen and nutrients damages the heart's muscle tissue – part of it essentially "dies." The damaged heart tissue does not contract as well which weakens the heart’s ability to pump blood.
Watch an animation of heart attack
Learn more at our Heart Attack Web site

High blood pressure (hypertension)
Uncontrolled high blood pressure increases your 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.
See an illustration of high blood pressure
Assess your risk of developing heart failure from high blood pressure
Learn more at our High Blood Pressure Web site

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.
Watch an animation of how the valves work
Watch an animation of heart valve disease
See an illustration of endocarditis
Learn more about heart valves

Heart muscle disease (dilated cardiomyopathy, hypertrophic 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.
Watch an animation of dilated cardiomyopathy
Watch an animation of hypertrophic cardiomyopathy
Learn more about cardiomyopathy

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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.
Learn more about living with congenital heart disease

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 increases the risk for developing heart failure. People with diabetes tend to develop hypertension and atherosclerosis from elevated lipid levels in the blood — both of which have been linked to heart failure.
Learn more about diabetes and heart disease

Other conditions
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.
Learn more at our Arrhythmia Web site

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

Treating and Living With Heart Failure

Heart failure caused by damage to the heart that has developed over time can't be cured. But it can be treated, quite often with strategies to improve symptoms.

Successful treatment depends on your willingness to get involved in managing this condition, whether you're the patient or a caregiver. You and your loves ones are an active part of the healthcare team.

Your treatment plan may include: