Heart failure is a long-term condition in which the heart cannot pump blood as effectively as the body needs. It does not mean that the heart has stopped. Heart failure can develop after damage to the heart or from conditions that make the heart work harder over time.
Common symptoms
- Shortness of breath during activity or when lying flat
- Unusual fatigue or weakness
- Swelling of the ankles, legs or abdomen
- Rapid weight gain caused by fluid retention
- Reduced ability to exercise
- Persistent cough or wheezing
- Fast or irregular heartbeat
Causes
Common causes include coronary artery disease, previous heart attack, high blood pressure, heart valve disease, cardiomyopathy and abnormal heart rhythms. Diabetes and other conditions can also increase risk.
Diagnosis
Assessment may include medical history, physical examination, blood tests, an electrocardiogram (ECG), chest imaging and an echocardiogram to evaluate heart structure and pumping function.
Treatment
Treatment depends on the type and cause of heart failure. It may include medicines that reduce symptoms and improve outcomes, treatment of underlying cardiovascular disease, lifestyle changes and cardiac rehabilitation. Some people need implanted devices, procedures or surgery.
When to seek urgent care
Seek emergency medical help for severe or sudden shortness of breath, chest pressure or pain, fainting, severe weakness, confusion or rapidly worsening breathing. People with known heart failure should seek prompt medical advice for rapidly increasing swelling, sudden weight gain or a clear deterioration in symptoms.
Related topics
Sources and further reading
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical assessment or treatment.