The symptoms of heart failure can vary from person to person. They may start suddenly or develop gradually over weeks or months.

The most common symptoms of heart failure are:

• breathlessness – this may occur after activity or at rest; it may be worse when you're lying down, and you may wake up at night needing to catch your breath
• fatigue – you may feel tired most of the time and find exercise exhausting
• swollen ankles and legs – this is caused by a build-up of fluid (oedema); it may be better in the morning and get worse later in the day
• feeling lightheaded and fainting

Other symptoms of heart failure can include:

• a persistent cough, which may be worse at night
• wheezing
• a bloated tummy
• loss of appetite
• weight gain or weight loss
• confusion
• a fast heart rate
• a pounding, fluttering or irregular heartbeat (palpitations)

Some people with heart failure may also experience feelings of depression and anxiety.

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

The symptoms can be caused by other, less serious conditions, so it's a good idea to get them checked out.

Read more about how heart failure is diagnosed.

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.

This is a medical emergency that may require immediate treatment in hospital.