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Symptoms - Atrial fibrillation

Many people with atrial fibrillation, particularly older people, do not have any symptoms.

The irregular heart rhythm is often only discovered during routine tests for another condition.

If atrial fibrillation is found, your doctor will check your symptoms and assess your risk of having a stroke. Usually you can start taking medicine right away. This is to stop your blood from clotting or to control your heart rhythm.

If you have symptoms, a cardioversion is usually carried out. This is where the heart is given a controlled electric shock to restore normal rhythm.

After this procedure many people with atrial fibrillation feel much better.

People can think tiredness and feeling lethargic is because of getting older. But when normal rhythm is restored, they realise these symptoms were caused by atrial fibrillation.

Heart palpitations

The most obvious symptom of atrial fibrillation is heart palpitations. This is where the heart feels like it's pounding, fluttering or beating irregularly, often for a few seconds or possibly a few minutes.

As well as an irregular heartbeat, your heart may also beat very fast. This could be often much higher than 100 beats per minute when resting.

You can work out your heart rate by checking your pulse in your neck or wrist.

Check your pulse (video) -

Other symptoms of atrial fibrillation can include:

  • tiredness and being less able to do physical activity
  • shortness of breath
  • feeling faint or lightheaded
  • chest pain

The way the heart beats in atrial fibrillation reduces the heart's performance and efficiency. This means the heart's ability to pump blood around the body well.

This can lead to low blood pressure (hypotension) and heart failure.

Non-urgent advice: Contact a GP if:

  • you have chest pain that comes and goes
  • you have chest pain that goes away quickly but you're still worried
  • you notice a sudden change in your heartbeat
  • your heart rate is often lower than 60 or above 100 and you have other symptoms of atrial fibrillation, such as dizziness and shortness of breath

Emergency action required: Call 112 if you have sudden chest pain that:

  • spreads to your arms, back, neck or jaw
  • makes your chest feel tight or heavy
  • also started with shortness of breath, sweating and feeling or being sick
  • lasts more than 15 minutes

You could be having a heart attack. You need immediate treatment in hospital.

Page last reviewed: 26 July 2023
Next review due: 26 July 2026