Symptoms of Atrial Fibrillation

The symptoms of atrial fibrillation can vary a lot from person to person, and even in the same person at different times. Palpitations are the most frequent symptom. While atrial fibrillation itself is not a life-threatening arrhythmia, it can lead to complications—in particular, stroke—that can be disabling or fatal. In most cases, at least before it is adequately treated, atrial fibrillation is a great annoyance, if not downright distressing and intolerable.

frequent symptoms of atrial fibrillation

Verywell / Nusha Ashjaee

Frequent Symptoms

The most common symptoms of atrial fibrillation are:

  • Palpitations
  • Easy fatiguability
  • Shortness of breath
  • Chest discomfort
  • Episodes of lightheadedness


Palpitations are most frequently associated with atrial fibrillation. These are unusual and uncomfortable moments of awareness of one's heartbeat. In atrial fibrillation, palpitations are caused by the rapid, irregular heart rate that is commonly seen with this arrhythmia.

People who experience palpitations with atrial fibrillation usually complain of the sensation of a “fluttering” in the chest, often accompanied by a feeling of “skipped” beats, and occasionally by brief episodes of lightheadedness. Palpitations associated with atrial fibrillation might be only mildly irritating, but they could also be extremely disturbing. Their severity can wax and wane.

In some, the severity of the palpitations may depend on their emotional state, whether they’re sitting or lying down, their state of hydration, whether or not they are sleep deprived, and several other factors related to daily life. Most of the time, however, no particular associations can be identified.

Palpitations are usually greatly diminished and often eliminated when the heart rate during atrial fibrillation is slowed with medications—a goal that can usually be accomplished quite readily.

Atrial Contraction-Related Symptoms

Also common with atrial fibrillation are reduced exercise tolerance, fatigue, dyspnea (shortness of breath), and even lightheadedness with almost any level of exertion. These symptoms are usually associated with the loss of cardiac efficiency that occurs when the atrial chambers are no longer able to beat effectively.

When atrial contraction is lost, the amount of blood the ventricles are able to eject with each heartbeat may become diminished. This limited cardiac output reduces a person’s exercise tolerance. Furthermore, when the atrial chambers stop beating effectively, the blood tends to “back up” into the lungs, producing shortness of breath.

In many people with atrial fibrillation, cardiac efficiency may be perfectly adequate at rest, but during exertion, when the heart is pushed to work harder, symptoms may become quite severe.

Rare Symptoms

Syncope, or an episode of loss of consciousness, is not common in atrial fibrillation. When syncope does occur, it is a strong clue that the patient may also have underlying sinus node disease, or sick sinus syndrome (SSS).

A minority of people with atrial fibrillation have no symptoms at all, and the arrhythmia is discovered only when a healthcare provider or nurse takes their pulse or performs an electrocardiogram (ECG).

Complications/Sub-Group Indications

Symptoms caused by the loss of effective atrial contractions tend to be much more troublesome in people who, in addition to atrial fibrillation, have cardiac conditions in which the ventricles are relatively “stiff.” Stiff ventricles tend to be highly dependent on a strong atrial contraction in order to fill completely. When atrial contractions are lost in these patients, cardiac efficiency may drop very significantly.

Conditions that tend to produce stiff ventricles include hypertrophic cardiomyopathydiastolic dysfunctionaortic stenosis, and even chronic high blood pressure (hypertension). In people with these conditions, the onset of atrial fibrillation commonly produces symptoms that are particularly severe.


In people who have coronary artery disease, the rapid heart rate seen with atrial fibrillation can cause angina (chest discomfort).

Sick Sinus Syndrome

Sick sinus syndrome (SSS) is a generalized disorder of the heart’s electrical system manifested by a slow heart rate (bradycardia).

The heart's natural pacemaker is the sinus node, an area of cells in right upper heart chamber (right atrium) where electrical signals are generated. The signals then travel to the rest of your heart muscle, signaling it to contract in rhythm. When there is damage or scarring to the heart, the electrical pathways from the sinus node may be disrupted, which leads to sick sinus syndrome.

Atrial fibrillation is common in patients with SSS. In a way, atrial fibrillation “protects” patients with SSS because it generally results in a heart rate that is fast enough to thwart symptoms of bradycardia, such as lightheadedness and weakness.

However, the atrial fibrillation often comes and goes periodically. When the arrhythmia suddenly stops, there is often a very long delay before the sick sinus node picks up again. That long pause before a heartbeat occurs is what produces syncope.

Treating SSS requires the use of a permanent pacemaker. In people who have both SSS and atrial fibrillation, it is usually best to insert the pacemaker before aggressive steps are taken to treat the atrial fibrillation (because this treatment often causes the heart rate to slow).

Heart Failure

For those with heart failure, the additional reduction in cardiac efficiency brought on by atrial fibrillation can greatly worsen symptoms—chiefly, shortness of breath, weakness, and swelling in the legs.

Rarely, atrial fibrillation can produce heart failure all by itself. Any arrhythmia that is capable of making the heartbeat very rapidly for several weeks or months can cause the heart muscle to weaken and lead to heart failure. Fortunately, this condition (tachycardia-induced heart failure) is a relatively rare consequence of atrial fibrillation.


Atrial fibrillation raises your risk of stroke to five times the usual risk. The increased risk of stroke is the main reason that it is always important to carefully consider the optimal treatment for atrial fibrillation—even in cases where the condition is well-tolerated and seems to be causing no particular problems.

Some people will have repeated episodes of atrial fibrillation without any symptoms whatsoever until they, at last, suffer a stroke. Only after the stroke occurs is it discovered that they are experiencing atrial fibrillation.

Evidence suggests that “subclinical” atrial fibrillation is more common than experts had realized and that unrecognized atrial fibrillation may be an important cause of cryptogenic stroke—that is, a stroke without an immediately apparent cause.

When to See the Healthcare Provider or Go to the Hospital

Palpitations, easy fatiguability, shortness of breath, chest discomfort, and episodes of lightheadedness or passing out are symptoms that you should always mention to your healthcare provider. Be sure to also share details on what led to these symptoms.

If you are having an episode of atrial fibrillation and your heart doesn't return to its normal rhythm in a few minutes, or your symptoms get worse, call your healthcare provider.

Seek immediate emergency medical help for these symptoms of a heart attack or stroke:

  • Pain or pressure in the middle of your chest
  • Face drooping
  • Arm weakness
  • Speech difficulty
  • Sudden numbness, especially on one side
  • Sudden severe headache
  • Sudden vision problems in one or both eyes
  • Sudden loss of balance or trouble walking

A Word From Verywell

If you have atrial fibrillation, your healthcare provider will ask you about all of these symptoms before recommending next steps. Try to be as accurate and complete as you can when sharing your medical history. This will help your healthcare provider better diagnose your condition and pick a treatment plan that's right for you. The two goals in treating atrial fibrillation are to prevent stroke and to control symptoms so that you can live a normal life.

Frequently Asked Questions

  • What are common atrial fibrillation triggers?

    An episode may come on during stress—in fact, about half of people with atrial fibrillation say stress is their most common trigger. It can also be triggered by other factors, such as a medication, caffeine, alcohol, or smoking. Other conditions, including sleep apnea, high blood pressure, and COPD, can also raise the risk of having an episode.

  • Does atrial fibrillation cause blood clots?

    Yes, it may. When the heart beats irregularly, blood can pool in the heart and clot there. As a result, blood clots may travel to the brain, causing a stroke. Blood clots can also block other arteries. This is one of the primary reasons Afib is considered a serious condition.

16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Richard N. Fogoros, MD
Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology.