Your heart never takes a break. Each day it beats approximately 100,000 times, pumping blood and providing oxygen and essential nutrients to your entire body. In an average lifetime, the heart beats more than 2.5 billion times.

A normal resting heart rate is 60 to 100 beats per minute. However, the heart doesn’t beat at its most efficient rate in people with atrial fibrillation. The irregular heart rhythm begins in the atria, or chambers of the heart. The atria may quiver irregularly or too rapidly, which leads to reduced blood flow through the other structures of the heart. When this happens, blood can build up in the heart and form a clot. A blood clot can be dangerous because it may cause a stroke if it travels to the brain. Atrial fibrillation increases the risk of stroke by 500 percent. Clots can also travel to other organs.

Aside from causing clots, atrial fibrillation can gradually weaken the heart and further impair its ability to pump blood efficiently. The condition may not always pose an immediate danger, but it’s important to recognize the symptoms so you can get a diagnosis and treatment.

Atrial Fibrillation Symptoms

The most common symptom of atrial fibrillation is a racing or fluttering heart rate. This occurs as a result of the atria quivering irregularly. You may feel like your heart is skipping a beat or beating too quickly or too hard. You may also feel a sudden pounding sensation in your chest.

Other common symptoms of atrial fibrillation include:

  • chest pain
  • fatigue
  • shortness of breath
  • weakness
  • lightheadedness
  • dizziness
  • fainting
  • confusion

It’s important to note that atrial fibrillation might not be an ongoing condition. Some people only experience atrial fibrillation occasionally, so their symptoms last for just a few minutes or a couple of hours. This is known as paroxysmal atrial fibrillation. Although the symptoms are short-lived, it’s beneficial to receive treatment.

Atrial Fibrillation Symptoms That Mimic Those of Other Conditions

Some of the most common symptoms of atrial fibrillation also resemble those of other heart conditions. These include:

Heart Attack

A heart attack happens when blood flow to the heart is abruptly cut off, causing tissue damage. This is usually the result of a blockage in one or more of the arteries. A blockage can form when a plaque builds up in the arteries.

Similar to those of atrial fibrillation, the most common symptoms of a heart attack include fatigue, shortness of breath, and chest pain. The pain may spread to other parts of the upper body, including the arms, neck, and jaw. You may also feel pressure or tightness in your chest if you’re having a heart attack.

The symptoms that can suggest a heart attack rather than an atrial fibrillation episode include:

  • nausea
  • vomiting
  • sweating
  • coughing

Call 911 immediately if you suspect that you or someone you know is having a heart attack. Don’t drive to the emergency room if you’re having chest pain. Instead, you should call 911 or have someone drive you to the emergency room.


A stroke occurs when blood flow to the brain is disrupted, depriving the brain tissue of oxygen. The two types of stroke are hemorrhagic and ischemic. A hemorrhagic stroke happens when blood vessels in the brain burst, causing blood to collect in the surrounding brain tissue. An ischemic stroke occurs when a blood clot blocks the flow of blood to the brain.

Many of the symptoms of both types of stroke mimic those of atrial fibrillation. Similar symptoms include weakness, fatigue, and dizziness. However, symptoms that commonly indicate a stroke rather than atrial fibrillation include:

  • facial drooping
  • difficulty speaking
  • a loss of vision
  • a severe headache
  • seizures

A stroke is a serious medical condition that must be treated immediately. Call 911 immediately if you think that you or someone you know is having a stroke.

Sick Sinus Syndrome (SSS)

Sick sinus syndrome (SSS) refers to a group of disorders that occur when the sinus node in your heart stops working correctly. The sinus node is the part of the heart that regulates heart rhythm. When the sinus node isn’t functioning properly, the heart can’t beat efficiently. SSS most often affects older adults.

The symptoms that resemble those of atrial fibrillation include an abnormal heartbeat and a slow pulse. Other similar symptoms include fainting, dizziness, or lightheadedness. Unlike people with atrial fibrillation, however, those with SSS may experience memory loss and disrupted sleep. Call your doctor if you have any of these symptoms. SSS must be treated to avoid complications.

When To See a Doctor

It’s important to note that atrial fibrillation doesn’t always cause symptoms. Many people live with atrial fibrillation without ever suspecting they have the condition. In fact, about one-third of Americans have atrial fibrillation but haven’t been diagnosed. Talk to your doctor about the tests that can be done to determine whether you have atrial fibrillation or another heart condition. You should also contact your doctor if you experience any symptoms of atrial fibrillation or if you believe your heart is beating differently and you don’t know why.