Heart failure — sometimes known as congestive heart failure — occurs when the heart muscle doesn't pump blood as well as it should. When this happens, blood often backs up and fluid can build up in the lungs, causing shortness of breath.
Certain heart conditions, such as narrowed arteries in the heart (coronary artery disease) or high blood pressure, gradually leave the heart too weak or stiff to fill and pump blood properly.
Proper treatment can improve the signs and symptoms of heart failure and may help some people live longer. Lifestyle changes — such as losing weight, exercising, reducing salt (sodium) in your diet and managing stress — can improve your quality of life. However, heart failure can be life-threatening. People with heart failure may have severe symptoms, and some may need a heart transplant or a ventricular assist device (VAD).
One way to prevent heart failure is to prevent and control conditions that can cause it, such as coronary artery disease, high blood pressure, diabetes and obesity.
Heart failure occurs when the heart muscle doesn't pump blood as well as it should. Blood often backs up and causes fluid to build up in the lungs (congest) and in the legs. The fluid buildup can cause shortness of breath and swelling of the legs and feet. Poor blood flow may cause the skin to appear blue (cyanotic). Some types of heart failure can lead to an enlarged heart.
Heart failure can be ongoing (chronic), or it may start suddenly (acute).
Heart failure signs and symptoms may include:
- Shortness of breath with activity or when lying down
- Fatigue and weakness
- Swelling in the legs, ankles and feet
- Rapid or irregular heartbeat
- Reduced ability to exercise
- Persistent cough or wheezing with white or pink blood-tinged mucus
- Swelling of the belly area (abdomen)
- Very rapid weight gain from fluid buildup
- Nausea and lack of appetite
- Difficulty concentrating or decreased alertness
- Chest pain if heart failure is caused by a heart attack
When to see a doctor
See your doctor if you think you might be experiencing signs or symptoms of heart failure. Call 911 or emergency medical help if you have any of the following:
- Chest pain
- Fainting or severe weakness
- Rapid or irregular heartbeat associated with shortness of breath, chest pain or fainting
- Sudden, severe shortness of breath and coughing up white or pink, foamy mucus
Although these signs and symptoms may be due to heart failure, there are many other possible causes, including other life-threatening heart and lung conditions. Don't try to diagnose yourself.
Emergency room doctors will try to stabilize your condition and determine if your symptoms are due to heart failure or something else.
If you have a diagnosis of heart failure and if any of the symptoms suddenly become worse or you develop a new sign or symptom, it may mean that existing heart failure is getting worse or not responding to treatment. This may also be the case if you gain 5 pounds (2.3 kilograms) or more within a few days. Contact your doctor promptly.
Chambers and valves of the heart
A typical heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of the heart. The heart valves, which keep blood flowing in the right direction, are gates at the chamber openings.
Enlarged heart, in heart failure
As the heart weakens, as it can with heart failure, it begins to enlarge, forcing the heart to work harder to pump blood on to the rest of the body.
Heart failure often develops after other conditions have damaged or weakened the heart. However, heart failure can also occur if the heart becomes too stiff.
In heart failure, the main pumping chambers of the heart (the ventricles) may become stiff and not fill properly between beats. In some people, the heart muscle may become damaged and weakened. The ventricles may stretch to the point that the heart can't pump enough blood through the body.
Over time, the heart can no longer keep up with the typical demands placed on it to pump blood to the rest of the body.
Your doctor can determine how well your heart is pumping by measuring how much blood is pumped out with each beat (ejection fraction). Ejection fraction is used to help classify heart failure and guide treatment. In a healthy heart, the ejection fraction is 50% or higher — meaning that more than half of the blood that fills the ventricle is pumped out with each beat.
But heart failure can occur even with a normal ejection fraction. This happens if the heart muscle becomes stiff from conditions such as high blood pressure.
Heart failure can involve the left side (left ventricle), right side (right ventricle) or both sides of your heart. Generally, heart failure begins with the left side, specifically the left ventricle — your heart's main pumping chamber.
|Type of heart failure
|Left-sided heart failure
||Fluid may back up in the lungs, causing shortness of breath.
|Right-sided heart failure
||Fluid may back up into the abdomen, legs and feet, causing swelling.
|Systolic heart failure (also called heart failure with reduced ejection fraction)
||The left ventricle can't contract vigorously, indicating a pumping problem.
|Heart failure with preserved ejection fraction
||The left ventricle can't relax or fill fully, indicating a filling problem.
Any of the following conditions can damage or weaken your heart and can cause heart failure. Some of these can be present without your knowing it:
Coronary artery disease and heart attack. Coronary artery disease is the most common form of heart disease and the most common cause of heart failure. The disease results from the buildup of fatty deposits in the arteries, which reduces blood flow and can lead to heart attack.
A heart attack occurs suddenly when a coronary artery becomes completely blocked. Damage to your heart muscle from a heart attack may mean that your heart can no longer pump as well as it should.
- High blood pressure. If your blood pressure is high, your heart has to work harder than it should to circulate blood throughout your body. Over time, this extra exertion can make your heart muscle too stiff or too weak to properly pump blood.
- Faulty heart valves. The valves of the heart keep blood flowing in the proper direction. A damaged valve — due to a heart defect, coronary artery disease or heart infection — forces the heart to work harder, which can weaken it over time.
- Damage to the heart muscle. Heart muscle damage can have many causes, including certain diseases, infection, heavy alcohol use, and the toxic effect of drugs, such as cocaine or some drugs used for chemotherapy. Genetic factors also can play a role.
- Inflammation of the heart muscle (myocarditis). Myocarditis is most commonly caused by a virus, including the COVID-19 virus, and can lead to left-sided heart failure.
- A heart problem that you're born with (congenital heart defect). If your heart and its chambers or valves haven't formed correctly, the healthy parts of your heart have to work harder to pump blood, which may lead to heart failure.
- Abnormal heart rhythms (arrhythmias). Abnormal heart rhythms may cause your heart to beat too fast, creating extra work for your heart. A slow heartbeat also may lead to heart failure.
- Other diseases. Long-term diseases — such as diabetes, HIV, an overactive or underactive thyroid, or a buildup of iron or protein — also may contribute to chronic heart failure.
Causes of sudden (acute) heart failure also include:
- Allergic reactions
- Any illness that affects the whole body
- Blood clots in the lungs
- Severe infections
- Use of certain medications
- Viruses that attack the heart muscle
A single risk factor may be enough to cause heart failure, but a combination of factors also increases your risk.
Risk factors for heart failure include:
- Coronary artery disease. Narrowed arteries may limit your heart's supply of oxygen-rich blood, resulting in weakened heart muscle.
- Heart attack. A heart attack is a form of coronary artery disease that occurs suddenly. Damage to your heart muscle from a heart attack may mean your heart can no longer pump as well as it should.
- Heart valve disease. Having a heart valve that doesn't work properly raises the risk of heart failure.
- High blood pressure. Your heart works harder than it has to if your blood pressure is high.
- Irregular heartbeats. These abnormal rhythms, especially if they are very frequent and fast, can weaken the heart muscle and cause heart failure.
- Congenital heart disease. Some people who develop heart failure were born with problems that affect the structure or function of their heart.
- Diabetes. Having diabetes increases your risk of high blood pressure and coronary artery disease. Don't stop taking any medications on your own. Ask your doctor whether you should make changes.
- Some diabetes medications. The diabetes drugs rosiglitazone (Avandia) and pioglitazone (Actos) have been found to increase the risk of heart failure in some people. Don't stop taking these medications on your own, though. If you're taking them, ask your doctor if you need to make any changes.
- Certain other medications. Some medications may lead to heart failure or heart problems. They include nonsteroidal anti-inflammatory drugs (NSAIDs); certain anesthesia medications; and certain medications used to treat high blood pressure, cancer, blood conditions, irregular or abnormal heartbeats, nervous system diseases, mental health conditions, lung and urinary problems, inflammatory diseases, and infections.
- Alcohol use. Drinking too much alcohol can weaken the heart muscle and lead to heart failure.
- Sleep apnea. The inability to breathe properly while you sleep results in low blood-oxygen levels and an increased risk of irregular heartbeats. Both of these problems can weaken the heart.
- Smoking or using tobacco. If you smoke, quit. Using tobacco increases your risk of heart disease and heart failure.
- Obesity. People who have obesity have a higher risk of developing heart failure.
- Viruses. Certain viral infections can cause damage to the heart muscle.
Complications of heart failure depend on the severity of heart disease, your overall health and other factors such as your age. Possible complications can include:
- Kidney damage or failure. Heart failure can reduce the blood flow to your kidneys, which can eventually cause kidney failure if left untreated. Kidney damage from heart failure can require dialysis for treatment.
- Heart valve problems. The valves of the heart, which keep blood flowing in the right direction, may not work properly if your heart is enlarged or if the pressure in your heart is very high due to heart failure.
- Heart rhythm problems. Heart rhythm problems may lead to or increase your risk of heart failure.
- Liver damage. Heart failure can cause fluid buildup that puts too much pressure on the liver. This fluid backup can lead to scarring, which makes it more difficult for your liver to work properly.
The key to preventing heart failure is to reduce your risk factors. You can control or eliminate many of the risk factors for heart disease by making healthy lifestyle changes and by taking the medications prescribed by your doctor.
Lifestyle changes you can make to help prevent heart failure include:
- Not smoking
- Controlling certain conditions, such as high blood pressure and diabetes
- Staying physically active
- Eating healthy foods
- Maintaining a healthy weight
- Reducing and managing stress