Atrial Fibrillation
Atrial fibrillation is an irregular heartbeat that often causes no symptoms at all, yet it is linked with roughly a fivefold increase in stroke risk, which is why finding it matters.
Medically reviewed by the RIIMS medical team · Last updated: June 2026
Go to hospital now
- Chest pain
- Severe shortness of breath
- Fainting or a sudden loss of consciousness
- Any stroke sign, facial drooping, arm weakness or slurred speech (F.A.S.T.): call emergency services even if it passes
See a doctor soon (not an emergency)
- A newly noticed irregular or racing pulse
- Breathlessness or tiredness that is new or worsening
What is atrial fibrillation, and why does it matter?
Atrial fibrillation, often shortened to AFib, is the most common irregular heart rhythm: the heart's upper chambers quiver instead of beating in a coordinated way, so blood does not move through them as smoothly as it should. Often there are no symptoms at all, and AFib is found only on an ECG done for another reason, or during a routine check. The reason AFib deserves attention even without symptoms is stroke risk: because blood can pool and clot in the quivering upper chambers, AFib is linked with roughly a fivefold increase in the risk of stroke compared with a normal heart rhythm. India's AFib picture differs from the West in an important way. Data from the Indian Heart Rhythm Society AFib registry shows Indian patients are more than a decade younger on average, and rheumatic valve disease, most often the result of rheumatic fever in childhood, is a major cause, present in close to half of registry patients. In the West, AFib is mostly a disease of older age with a different set of causes. A younger person here should never assume AFib is unlikely just because of their age, and an echocardiogram, not only an ECG, is often the test that actually finds the underlying valve problem driving it.
Symptoms to watch for
- Often no symptoms at all; found only on an ECG or routine check
- A fluttering, racing or irregular heartbeat, when noticed
- Tiredness or reduced ability to exercise
- Breathlessness on exertion
- Lightheadedness
- A pulse that feels irregular when checked manually
When to consult a doctor
If you notice an irregular or racing pulse, get it checked with an ECG. Because AFib is often silent, anyone with rheumatic heart disease, unexplained breathlessness, or a stroke at a young age in the family should ask specifically whether their heart rhythm has ever been checked.