Heart failure means that the heart is unable to pump blood around the body properly. It usually occurs because the heart has become too weak or stiff.

It's sometimes called "congestive" heart failure, although this name isn't widely used nowadays.

Heart failure doesn't mean your heart has stopped working – it just needs some support to help it work better. It can occur at any age, but is most common in older people.

Heart failure is a long-term condition that tends to get gradually worse over time. It can't usually be cured, but the symptoms can often be controlled for many years.

Symptoms of heart failure

The main symptoms of heart failure are:

• breathlessness after activity or at rest
• feeling tired most of the time and finding exercise exhausting
• swollen ankles and legs

Some people also experience other symptoms, such as a persistent cough, a fast heart rate, and dizziness.

Symptoms can develop quickly (acute heart failure) or gradually over weeks or months (chronic heart failure).

Read more about the symptoms of heart failure.

When to get medical advice

See your GP if you experience persistent or gradually worsening symptoms of heart failure.

Call 999 for an ambulance or go to your nearest accident and emergency (A&E) department as soon as possible if you have sudden or very severe symptoms.

A number of tests can be used to help check how well your heart is working, including blood tests, an electrocardiogram (ECG) and an echocardiogram.

Read more about how heart failure is diagnosed.

Causes of heart failure

Heart failure is often the result of a number of problems affecting the heart at the same time.

Conditions that can lead to heart failure include:

• coronary heart disease – where the arteries that supply blood to the heart become clogged up with fatty substances (atherosclerosis), which may cause angina or a heart attack
• high blood pressure – this can put extra strain on the heart, which over time can lead to heart failure
• cardiomyopathy – conditions affecting the heart muscle
• heart rhythm problems (arrhythmias) – such as atrial fibrillation
• damage or other problems with the heart valves
• congenital heart disease – birth defects that affect the normal workings of the heart

Sometimes anaemia, excessive alcohol consumption, an overactive thyroid, or high pressure in the lungs (pulmonary hypertension) can also lead to heart failure.

Treatments for heart failure

Treatment for heart failure usually aims to control the symptoms for as long as possible and slow down the progression of the condition.

Common treatments include:

• lifestyle changes – including eating a healthy diet, exercising regularly and stopping smoking
• medication – a range of medicines can help; many people need to take two or three different types
• devices implanted in your chest – these can help control your heart rhythm
• surgery – such as a bypass operation or a heart transplant

Treatment will usually be needed for life.

A cure may be possible when heart failure has a treatable cause. For example, if your heart valves are damaged, replacing or repairing them may cure the condition.

Read more about how heart failure is treated and living with heart failure.

Outlook for heart failure

Heart failure is a serious long-term condition that will usually continue to get slowly worse over time.

It can severely limit the activities you're able to do and is often eventually fatal.

But it's very difficult to predict how the condition will progress on an individual basis. It's very unpredictable – many people remain stable for many years, while in some cases it may get worse quickly.

Overall, around half of people with heart failure live at least five years after their diagnosis.