Atrial fibrillation (AF or Afib) is a type of arrhythmia in which your heart beats irregularly and often fast.
This reduces your heart’s ability to pump blood properly and increases the chance of a blood clot forming in your heart and travelling up to your brain, where it can cause a stroke.
The common symptoms of atrial fibrillation include: feeling breathless, feeling faint, dizzy or lightheaded, racing heart (palpitations), tiredness or weakness, chest discomfort and difficulty exercising.