What are the Symptoms of Atrial Fibrillation?

Common symptom: A quivering or fluttering heartbeat

Atrial fibrillation, also called AFib or AF, is the most common type of irregular heartbeat. The abnormal firing of electrical signals causes the top chambers in the heart (atria) to quiver (or fibrillate). View an animation of AFib.

More common symptoms of AFib

Sometimes, people with AFib have no symptoms, and their condition is found only with a physical exam. Others may have one or more of these symptoms:

• General tiredness (fatigue)
• Rapid and irregular heartbeat
• Fluttering or “thumping” in the chest
• Dizziness
• Shortness of breath and anxiety
• Weakness
• Faintness or confusion
• Fatigue when exercising
• Sweating
• Chest pain or pressure (This is a medical emergency. You may be having a heart attack. Call 911 right away if you have one of these symptoms.)

Track your AFib symptoms (PDF) | Spanish (PDF)

Are there different types of AFib?

There are different types of AFib. The symptoms are generally the same. But, the length of the AFib and reasons for it can help health care professionals classify the type of AFib problem.

• Paroxysmal fibrillation is when the heart returns to a normal rhythm on its own or with help within seven days. People who have this type of AFib may have episodes only a few times a year, or it may happen every day. These symptoms are random and can often become a permanent form of AFib.
• Persistent AFib is an irregular rhythm that lasts longer than seven days. This type of AFib will not return to a normal sinus rhythm on its own and will need some form of treatment.
• Longstanding AFib is when the heart is constantly in an irregular rhythm for longer than 12 months.
• Permanent AFib occurs when the condition doesn’t end, and the patient and doctor have decided to stop trying to restore a normal rhythm.

All types of AFib, if not treated, can increase your risk of stroke. Even with no symptoms, you are up to nearly five times more likely to have a stroke than someone who doesn’t have AFib.

Common AFib-related terms

You may hear these terms when talking about your symptoms and treatment with health care professionals.

• Sinus rhythm is the heart’s normal rhythm. The sinus node in the heart creates an electrical signal that causes the heart to beat.
• Bradycardia is a slower than normal heart rate.
• Tachycardia is a faster than normal heart rate.
• Atrial flutter is an abnormal heart rhythm not as common as AFib.
• Palpitation is a feeling that your heart is racing or pounding. Palpitations can be caused by diet, stress and health problems. Health care professionals can help learn the cause.

How are heart attack symptoms different from AFib symptoms?

Fluttering and palpitations are more common symptoms of AFib than a heart attack. But many heart problems have similar symptoms. If you think you may be having a heart attack, don’t delay. Get emergency help by calling 911 right away.

A heart attack is a blockage of blood flow to the heart. This is often caused by a clot or buildup of plaque in the blood vessel that carries blood to part of the heart muscle (coronary artery). A heart attack can damage or destroy part of your heart muscle. Some heart attacks are sudden and intense. Most start slowly, with mild pain or discomfort. Often people affected aren’t sure what's wrong and wait too long before getting help.

Everyone with AFib should know symptoms of a heart attack or stroke

Having AFib can increase your risk for stroke and heart attack. Here are the symptoms you should know:

Heart attack symptoms

Chest discomfort

Most heart attacks involve discomfort in the center of the chest that lasts more than a few minutes or that goes away and comes back. It can feel like uncomfortable pressure, squeezing, fullness or pain.

Discomfort in other areas of the upper body

Symptoms can include pain or discomfort in one or both arms, the back, neck, jaw or stomach.

Shortness of breath

With or without chest discomfort.

Other signs

Breaking out in a cold sweat, rapid or irregular heartbeat, feeling unusually tired, nausea or lightheadedness.

Stroke symptoms

Spot a stroke F.A.S.T., whether these symptoms are what you are feeling or you notice them in someone else:

• Face drooping: Does one side of the face droop, or is it numb? Ask the person to smile.
• Arm weakness: Is one arm weak or numb? Ask the person to raise both arms. Does one arm drift downward?
• Speech difficulty: Is their speech slurred? Are they unable to speak, or are they hard to understand? Ask the person to repeat a simple sentence such as, “The sky is blue.” Could they repeat the sentence correctly?
• Time to call 911: If the person shows any of these symptoms, even if the symptoms go away, call 911 and get them to the hospital right away.