Health Topic

Atrial Fibrillation

Atrial fibrillation (AF or AFib) is the most common type of arrhythmia (irregular heartbeat). Read about symptoms and treatment.

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Also called: AF · AFib

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Atrial Fibrillation

Atrial fibrillation, also known as AFib or AF, is one of the most common types of arrhythmias. Arrhythmias are problems with the rate or rhythm of your heartbeat. They can cause your heart to beat too slowly, too fast, or in an irregular way.

If you have AFib, your heart beats irregularly and sometimes much faster than normal. Also, your heart's upper and lower chambers do not work together as they should. When this happens, the lower chambers do not fill completely or pump enough blood to your lungs and body. This can cause symptoms such as dizziness, fatigue, and a pounding heartbeat.

AFib may happen in brief episodes, or it may be a permanent condition. It's very important to treat it, since AFib can put you at risk for stroke and other heart conditions.

AFib is most often caused by changes to the heart's tissue or the electrical signaling that helps the heartbeat. These changes can happen due to different conditions and factors, such as high blood pressure, coronary artery disease, congenital heart defects, infections, and aging. Sometimes the cause is unknown.

Anyone can develop AFib, but there are certain things that raise your risk for it:

  • Aging. The risk of atrial fibrillation increases as you get older, especially when you are over age 65.
  • Family history and genetics. AFib can run in families. So can heart disease, which raises your risk of AFib.
  • Some lifestyle choices. Your risk is higher if you drink a lot of alcohol, use certain illegal drugs such as cocaine and methamphetamines, or smoke.
  • Having certain health conditions, such as: High blood pressure
  • Diabetes
  • Heart failure
  • Heart valve diseases
  • Obesity
  • Hyperthyroidism
  • Chronic kidney disease
  • COPD and other lung diseases
  • Sleep apnea

Some people who have AFib don't have any symptoms and don't know they have it. If you do have symptoms, you may only notice them once in a while. Or you may have symptoms that are more frequent. And in some cases, the symptoms might be severe. If you have heart disease, you are more likely to notice your symptoms. And those symptoms could get worse if your heart disease gets worse.

The symptoms of AFib can include:

  • Extreme fatigue, which is the most common symptom
  • Heart palpitations (the feeling that your heart is skipping a beat, fluttering, pounding, or beating too hard or too fast)
  • Trouble breathing, especially when lying down or when exercising
  • Chest pain
  • Dizziness or fainting
  • Low blood pressure

If AFib is not treated, it can lead to serious health problems (complications) such as:

  • Stroke
  • Heart failure
  • Blood clots
  • Sudden cardiac arrest (SCA)
  • Cognitive impairment and dementia

To help prevent these problems, it's important to contact your health care provider if you are having symptoms. If you do have AFib, the sooner you are diagnosed and treated, the better.

To find out if you have AFib, your provider:

  • Will ask about your medical history, including your symptoms, lifestyle, and any other health conditions you may have
  • Will ask about your family history, to find out if you have relatives who have or had AFib
  • Will do a physical exam
  • May order blood tests
  • Will likely order heart tests, such as an electrocardiogram (also called an EKG or ECG) and echocardiogram
  • May ask you to wear a heart monitor device that records your heart's electrical activity

The treatments for AFib may include:

  • Blood thinner medicines that help prevent blood clots from forming.
  • Medicines to control your heart's rhythm and rate.
  • Following heart-healthy lifestyle changes, such as: Following a heart-healthy eating plan that limits saturated fats, salt, and cholesterol. An example is the DASH eating plan.
  • Limiting or avoiding alcohol, because it can increase your heart rate.
  • Aiming for a healthy weight.
  • Getting regular physical activity.
  • Managing stress.
  • Quitting smoking.
  • Electrical cardioversion, which restores your heart rhythm using low-energy shocks to your heart.
  • Catheter ablation, which scars the tissue that is causing the arrhythmia. The scar tissue blocks the abnormal heart signals.
  • Surgery to put in a pacemaker to help control the arrhythmia.
  • A Maze procedure, which creates scar tissue in a maze-like pattern in certain parts of the heart.
  • Left atrial appendage closure, a surgery on a small sac in the muscle wall of your left atrium (the upper left chamber of your heart). It helps prevent blood clots and can reduce your risk of stroke. This surgery is for people who are not able to take blood thinners.

There are steps you can take to help lower your risk of atrial fibrillation, such as:

  • Making heart-healthy lifestyle changes: Following a heart-healthy eating plan
  • Limiting or avoiding alcohol
  • Aiming for a healthy weight
  • Getting regular physical activity
  • Managing stress
  • Not smoking

It sits within Blood, Heart and Circulation.

The lead U.S. institute for this subject is the National Heart, Lung, and Blood Institute.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Atrial Fibrillation

4,124 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Diagnosis and Tests

Treatments and Therapies

Prevention and Risk Factors

Related Issues

Genetics

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Atrial Fibrillation. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Atrial Fibrillation, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.