What Is Atrial Fibrillation (A-Fib)?

Atrial fibrillation, also called A-fib, is the most common type of heart arrhythmia. In fact, A-fib affects an estimated 3-6 million people in the United States alone. With A-fib, the upper heart chambers (the atria) beat irregularly. As a result, blood doesn’t move well into the lower heart chambers (the ventricles). 

The risk of A-fib goes up with age. Still, other risk factors, like high blood pressure or diabetes, can increase your odds of developing the condition. Symptoms don’t always appear but may include heart palpitations, lightheadedness, or chest pain.

Some people experience A-fib in brief episodes, whereas it’s a permanent condition for others. If left untreated, A-fib increases your chances of stroke fivefold. Luckily, there are many treatment options that can resolve A-fib or keep it under control.


There are four primary types of atrial fibrillation. They include:

  • Paroxysmal atrial fibrillation: Also known as occasional A-fib, paroxysmal A-fib lasts less than one week and typically goes away without treatment. A-fib symptoms come and go. 
  • Persistent atrial fibrillation: Persistent A-fib sticks around longer than one week and requires treatment. Treatment is needed to restore a normal heart rhythm
  • Long-standing persistent atrial fibrillation: Long-standing persistent A-fib lasts more than a year and can be challenging to treat.
  • Permanent atrial fibrillation: In permanent A-fib, an irregular heart rhythm can’t be fixed. It calls for medications to keep the heart rate under control and prevent blood clots. 

It is possible for A-fib to progress over time, starting as paroxysmal and becoming persistent to long-term.

A-fib Symptoms

Some people who have A-fib don’t have symptoms and may not know they have it. However, many people with A-fib notice one or more of the following symptoms:

  • Heart palpitations: This is the most common A-fib symptom. Think of heart palpitations as noticeable sensations in the chest from the irregular heartbeat. 
  • Fatigue or weakness: You may feel extreme fatigue or weakness with A-fib. This is because the heart can’t pump enough oxygenated blood through your body. 
  • Dizziness or lightheadedness: When your heart isn't working well, your brain may not get enough blood. This blood shortage can make you dizzy or lightheaded. 
  • Shortness of breath (dyspnea): Some people with A-fib experience dyspnea even when resting. When the heart doesn’t pump blood effectively, fluid can build up in the lungs. This makes it harder to breathe.
  • Chest pain (angina): When your heart doesn’t get enough blood, you may experience chest pain, known as angina. You may feel pressure or squeezing in your chest. 

What Causes A-fib?

Normally, your heart’s electrical system tells the upper chambers (the atria) to contract at the same time. This pumps blood into the lower heart chambers (the ventricles). Then, the electrical system signals the ventricles to contract, sending blood to your lungs and the rest of your body. But if you have A-fib, your heart’s electrical system gets thrown off rhythm. When this happens, your heart can’t contract or pump blood effectively. 

A-fib often occurs when your heart’s tissue or the electrical system that signals the heartbeat change or become damaged. Often, the changes that trigger A-fib are caused by other health conditions, such as high blood pressure (hypertension) and coronary heart disease.

Risk Factors

The older you get, the greater your risk for A-fib. Your risk of developing A-fib also increases with the following health conditions:

  • Hypertension
  • Type 2 diabetes
  • Heart failure
  • Heart valve diseases
  • Overactive thyroid (hyperthyroidism)
  • Sleep apnea
  • Chronic obstructive pulmonary disease (COPD)

Certain lifestyle habits, such as smoking and drinking alcohol, can also raise your risk.


To diagnose A-fib, your healthcare provider will take your medical history and ask about your lifestyle habits and symptoms. Your provider will then listen to your heart with a stethoscope and take your pulse and blood pressure. They may also perform basic tests to rule out thyroid problems, heart failure, and lung infection.

In addition, your healthcare provider may conduct the following diagnostic tests:

  • Electrocardiogram (EKG or ECG): An EKG measures and records your heart’s electrical signals to see if your heart beats normally. 
  • Echocardiogram (echo): An echo uses sound waves to create images of the heart to check blood flow and contractions. 
  • Blood test: A blood test can be used to measure your potassium and thyroid hormone levels (TSH) in the event a blood imbalance is the cause of A-fib. 

Treatments for A-fib

The primary goals for treating A-fib include controlling your heart rate, restoring a normal heart rhythm, and lowering your risk of stroke. Treatment may include various prescription medications and procedures.

Prescription Medications

Medication is often the first treatment your healthcare provider will try. Options include:

  • Beta blockers: These medications slow your heart rate so your ventricles have enough time to fill completely with blood.
  • Blood thinners: Blood thinners prevent blood clots, lowering your risk of stroke. 
  • Calcium channel blockers: These medications help control how quickly your ventricles pump blood. 
  • Rhythm control medications: As the name suggests, these medications help control your heart rhythm. 

Procedures and Surgeries

If medications don’t fix your A-fib, your healthcare provider may recommend surgery. Common procedures include: 

  • Electrical cardioversion: This procedure “resets” your heart rhythm with low-energy shocks. 
  • Catheter ablation: This procedure uses radiofrequency waves, extreme cold, or laser light to destroy any tissue that’s causing the arrhythmia.
  • Pacemaker: Pacemakers are devices that are inserted into your body to support your heart’s electrical system. It’s used if you have a slow heart rate and another arrhythmia in addition to A-fib.
  • Left atrial appendage closure: This surgery involves plugging, closing, or cutting off a small sac in your left atrium to prevent blood clots. It’s often used if you can’t take blood thinners.
  • MAZE procedure: This surgery creates scars in the left atrium to help your heart beat normally. It’s typically done in people having open heart surgery for other heart diseases. 


Some factors that raise your risk of A-fib can’t be changed. These include your age, family history, and any congenital health conditions you may have.

However, certain lifestyle choices help prevent changes to your heart that can cause A-fib. Use these A-fib prevention tips to lower your risk:

  • Reduce or eliminate alcohol 
  • Add aerobic exercise to your routine, such as brisk walking, biking, or jogging
  • Avoid smoking and using tobacco
  • Eat a heart-healthy diet

Comorbid Conditions

Having A-fib increases your risk of developing health conditions such as:

  • Ischemic stroke: When A-fib keeps the heart from pumping blood properly, the blood can form a clot. If the clot travels through the blood to other parts of the body, it may block blood flow to organs. When a blood clot blocks the blood supply to the brain, you can have an ischemic stroke. In fact, having A-fib increases your risk of stroke fivefold.
  • Heart failure: Heart failure is a condition in which the heart can’t pump enough blood to meet your needs. Because A-fib limits how well the heart pumps blood, it can increase your risk of developing heart failure.
  • Dementia: Dementia is a general term for memory loss and other thinking problems that interfere with daily life. Alzheimer’s disease is the most common cause of dementia. A-fib may increase your odds of dementia due to reduced blood flow to the brain.

Living With A-fib

For some people, A-fib resolves on its own. For others, A-fib can often be treated and managed through medications and surgery. 

However, A-fib can lead to health complications if undetected or untreated. This is especially important to know if you’re a Black American. While white Americans have A-fib at higher rates, Black Americans are more likely to have serious complications like stroke and heart failure.

Staying on top of your care is key to seeing improvement and avoiding complications. So if you’ve been diagnosed with A-fib, follow your treatment plan and attend all your doctor appointments.

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15 Sources
Health.com 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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