What is heart failure?
Heart failure does not mean the heart has stopped working, but the heart's pumping power has become weakened.
With heart failure, blood moves through the heart and body at a slower rate, and pressure in the heart increases. As a result, the heart cannot pump enough oxygen and nutrients to meet the body's needs. The chambers of the heart respond by stretching to hold more blood to pump through the body or by becoming stiff and thickened. This helps to keep the blood moving for a short while but, in time, the heart muscle walls weaken and are unable to pump as strongly. As a result, the kidneys often respond by causing the body to retain fluid (water) and sodium. If fluid builds up in the arms, legs, ankles, feet, lungs or other organs, the body becomes congested, and congestive heart failure is the term used to describe the condition.
Around 900,000 people in the UK have heart failure.
What causes heart failure?
Heart failure is caused by many conditions that damage the heart muscle, including:
- Coronary artery disease. Coronary artery disease (CAD), a disease of the arteries that supply blood and oxygen to the heart, causes decreased blood flow to the heart muscle. If the arteries become blocked or severely narrowed, the heart becomes starved of oxygen and nutrients.
- Heart attack. A heart attack may occur when a coronary artery becomes suddenly blocked, stopping the flow of blood to the heart muscle and damaging it. All or part of the heart muscle becomes cut off from its supply of oxygen. A heart attack can damage the heart muscle, resulting in a scarred area that does not function properly.
- Cardiomyopathy. Damage to the heart muscle from causes other than artery or blood flow problems, such as from infections or alcohol or drug use. Cardiomyopathy is often inherited and runs in families.
- Conditions that overwork the heart. Conditions including high blood pressure (hypertension), valve disease, thyroid disease, kidney disease, diabetes or heart defects present at birth can all cause heart failure.
What are the symptoms of heart failure?
You may not have any symptoms of heart failure, or the symptoms may be mild to severe. Symptoms can be constant or come and go. The symptoms can include:
- Shortness of breath. Fluid back-up in the lungs can cause shortness of breath with exercise or difficulty breathing at rest or when lying flat in bed. Lung congestion can also cause a dry, hacking cough or wheezing.
- Fluid and water retention ( oedema). Less blood to your kidneys causes fluid and water retention, resulting in swollen ankles, legs, abdomen (called oedema) and weight gain. Symptoms may cause an increased need to urinate during the night. Bloating in your stomach may cause a loss of appetite or nausea.
- Dizziness, fatigue and weakness. Less blood to your major organs and muscles makes you feel tired and weak. Less blood to the brain can cause dizziness or confusion.
- Rapid or irregular heartbeats. The heart beats faster to pump enough blood to the body. This can cause a fast or irregular heartbeat.
If you have heart failure, you may have one or all of these symptoms or none of them. In addition, your symptoms may not be related to how weak your heart is; you may have many symptoms but your heart function may be only mildly weakened. Or you may have a more severely damaged heart but have no symptoms.