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Understanding Atrial Fibrillation: Symptoms, Causes, Prevention, and Treatment

Written by 
Angela Myers
Reviewed by 
Melissa Frost, NP

Article at a glance

  • Atrial fibrillation is the most common reason for an irregular heartbeat.
  • There are many causes of atrial fibrillation, including non-cardiac and cardiac conditions. 
  • Atrial fibrillation can cause a range of symptoms and serious complications, such as heart failure, stroke, and sudden cardiac arrest.

Atrial fibrillation is a common heart arrhythmia, a condition where the heart beats irregularly. A 2020 study estimates one in four older adults in Europe and the United States will develop this heart condition within their lifetime. 

If someone is diagnosed with atrial fibrillation, it’s important to understand the causes, symptoms, and treatment options. This article dives into all three and provides some heart-healthy habits that can help prevent or treat atrial fibrillation.

What Is Atrial Fibrillation (AFib)?

Atrial fibrillation (sometimes called AFib) is one of the most common types of cardiovascular disease. When someone has this condition, their heart beats irregularly, usually faster than it should. This irregular heartbeat causes an ineffective blood flow from the heart’s upper chambers to the lower ones. 

AFib can lead to deadly complications, such as heart failure, blood clots, and cardiac arrest. In 2019 alone, atrial fibrillation was mentioned on 183,321 death certificates. It’s also on the rise, with the CDC estimating 12.1 million Americans will have AFib by 2030. 

Fortunately, medical researchers understand more about this condition than ever before, and treatment options are becoming more effective. 

Types of Atrial Fibrillation

The type of atrial fibrillation someone has depends on how long the symptoms last or what causes the irregularity. This should be determined by a doctor, and the type often impacts treatment. 

Types of atrial fibrillation include:

  • Paroxysmal atrial fibrillation: the abnormal heart rhythm lasts 24 hours to seven days
  • Persistent AFib: the irregular heartbeat persists for longer than seven days 
  • Longstanding AFib: the heartbeat is irregular for twelve months or longer
  • Permanent AFib: the heartbeat remains irregular indefinitely
  • Nonvalvular AFib: the final type is the only one not caused by a lack of coherence between the upper and lower chambers. Instead, nonvalvular AFib is caused by a problem with the heart valve. 

Paroxysmal AFib is the only type where the heartbeat can return to a normal sinus rhythm without treatment, though episodes of abnormal heartbeats can occur repeatedly. All other types, except permanent AFib, require treatment. 

Atrial fibrillation is only classified as permanent if doctors and the patient decide it’s not possible to restore a normal heart rhythm after treatment. 

What Causes Atrial Fibrillation?

There isn’t one cause for atrial fibrillation. Instead, the condition can result from various problems, including changes in the tissue in the heart or electrical signaling. For some AFib diagnoses, the cause is unknown.

Specific cardiac conditions have been linked to atrial fibrillation. These include:

  • Cardiomyopathy, conditions that affect heart muscle
  • Congenital heart disease or congenital heart defect, conditions caused by structural problems in the heart 
  • Coronary artery disease, conditions caused by the buildup of harmful material in the coronaries
  • Hypertensive heart disease, when blood pressure elevation changes the coronaries, left ventricle, or left atrium 
  • Infiltrative cardiac disease, conditions with abnormal materials in the heart tissue
  • Pre-excitation syndrome, when electrical impulses in the atria excite earlier than they should
  • Sick sinus syndrome, heart rhythm problems caused by a dysfunctional sinus node
  • Heart valve disease, when one or more heart valves are damaged

Some non-cardiac conditions can also cause AFib, including:

  • Acute infections, such as sepsis and pneumonia
  • Electrolyte abnormalities, usually due to too little or too much water
  • Hypothermia, when the body loses heat too quickly for it to be replaced
  • Lung disease, especially if chronic
  • Pheochromocytoma, a tumor often found in the adrenal gland
  • Pulmonary embolism, a blockage in pulmonary arteries 
  • Thyroid disorders, especially those causing hyperthyroidism (an overactive thyroid gland) 

Atrial fibrillation can also be a complication of various cardiac surgeries. A 2022 study estimates that 20–55% of cardiac surgery operations result in atrial fibrillation. 

Risk Factors for Atrial Fibrillation

Anyone can be diagnosed with Atrial Fibrillation, but some risk factors increase someone’s chances of developing this irregular heart rhythm. Certain risk factors include:

  • Family history: if a family member has AFib, someone has a higher chance of developing the condition as well
  • Genetics: atrial fibrillation is more common in those with European ancestry
  • Recent cardiac surgery
  • Age: atrial fibrillation is more common in those over 65 
  • Medical history: certain health conditions such as, chronic kidney disease, chronic obstructive pulmonary disease (COPD), diabetes, high blood pressure, obesity, various heart conditions, and obstructive sleep apnea, increase the likelihood of AFib
  • Lifestyle: those with an unhealthy lifestyle (lack of regular exercise, drinking and/​or smoking in excess, eating an unbalanced diet, etc.) are more likely to develop AFib

Note: The final risk factor, lifestyle, is controllable. Those who abstain from smoking and drinking in excess, move their body regularly, and eat a heart-healthy diet are less likely to develop atrial fibrillation. 

Symptoms of AFib

The most common symptom of atrial fibrillation is an irregular heartbeat. Some describe AFib as a fast, fluttering, or pounding heartbeat. Others don’t feel any new sensations or symptoms, which is part of why AFib is hard to diagnose and treat. 

Along with heartbeat changes, AFib symptoms can include:

  • Fatigue 
  • Fainting or dizziness
  • Confusion
  • Trouble breathing 
  • Pain in chest
  • Anxiety

A common problem with diagnosing AFib is that symptoms vary widely. Someone with atrial fibrillation can experience no symptoms, while others display symptoms once in a while or have daily symptoms. Untreated AFib can lead to complications, like stroke and heart failure, and in severe cases death, which is why it’s important to regularly visit your primary care provider to receive necessary screenings, tests, and check-ups. 

Heart Failure

Heart failure is one of the most common complications of atrial fibrillation. Heart failure occurs when the heart can’t pump enough blood to fulfill the body’s needs. Like AFib itself, heart failure has a wide range of symptoms.

If someone has mild heart failure, they may feel weak after physical work and have few to no other symptoms. Severe heart failure, on the other hand, can lead to death. The exact symptoms and severity depend on whether the right or left side of the heart is affected. It’s estimated having AFib increases someone’s risk of developing heart failure by 300%.

If you’re experiencing ongoing fatigue or weakness, it’s important to contact your doctor and get to the root of the issue.

Blood Clots

Platelets, cells, or proteins sometimes stick together in the bloodstream. When this occurs, a blood clot forms. There are many reasons blood may clot, including a disruption in how much blood the heart pumps out due to atrial fibrillation. 

Blood clots can form in the brain, heart, lungs, kidneys, or other vital organs and can travel between them. 

Problems caused by blood clots vary widely, depending on where they are within the body. They range from deep vein thrombosis (DVT) to life-threatening conditions, such as a heart attack or stroke.

Note: To learn more about the signs of a blood clot and how to prevent them, visit this source.

Sudden Cardiac Arrest (SAC)

Sudden cardiac arrest (SAC) is when the heart stops beating. Since the heart pumps blood throughout the body, a paused heartbeat can cause the body to shut down. When untreated, SAC causes death in minutes. Fortunately, a defibrillator may prevent death if used quickly. 

The reason why atrial fibrillation causes SAC is unclear, and some researchers even argue AFib doesn’t cause SAC, but that both SAC and AFib can be caused by one overarching condition, such as coronary heart disease. Nonetheless, those with AFib are more likely to experience SAC.

If someone has SAC, the first symptom is losing consciousness. When this happens, call 911 immediately. 


Atrial fibrillation can cause blood clots in the heart, which might travel to the brain. Once in the brain, clots block off the blood supply. Without proper blood flow, parts of the brain are damaged or die, resulting in a stroke.

A stroke can cause numbness on the face, arm, and/​or leg, with the numbness usually on one side of the body. It also results in difficulty seeing, speaking, and walking and severe headaches. 

If someone is suspected of having a stroke, they need immediate medical care. Strokes can cause disabilities, brain damage, and death, especially if left untreated. 

Note: For more information on the warning signs of stroke, visit this source.

Cognitive Impairments

The final serious complication with atrial fibrillation is cognitive impairments. AFib can create blood clots which may travel to the brain, causing damage. 

Usually, the result of these cognitive impairments is memory issues, including dementia and Alzheimer’s disease. 

Note: To learn more about the warning signs of dementia, visit this source. To learn more about the warning signs of Alzheimer’s, visit this source.

Atrial Fibrillation Diagnosis

If someone is experiencing symptoms of atrial fibrillation, they should contact a healthcare provider. Often, a primary care physician can run some preliminary tests, though they will likely refer a patient to a cardiologist. 

Depending on someone’s age, a primary care doctor may check for warning signs of atrial fibrillation or atrial flutter during a physical exam. They can also provide recommendations to prevent atrial fibrillation.

How is Atrial Fibrillation Diagnosed?

To diagnose AFib, a primary care doctor or cardiologist will ask about someone’s medical and family history, the symptoms they are experiencing, and their lifestyle. They will also run a series of tests, including:

  • Blood tests to check potassium or thyroid hormone levels
  • Heart tests, such as an electrocardiogram
  • A heart monitor assessment, where a patient goes about their day as usual or completes tasks in a doctor’s office, such as walking on a treadmill, with a monitor on. 

Once atrial fibrillation has been diagnosed, a cardiologist will design a treatment plan. 

AFib Treatment

Atrial fibrillation is not something that can be cured with at-home remedies. Instead, patients should consult a cardiologist and follow their recommended treatment plan. 

The most common treatments aim to restore normal rhythm, avoid other heart-related complications like ischemic stroke or sudden cardiac arrest, or prevent long-standing persistent AFib. These treatments may include anything from lifestyle changes to heart surgery.


Medications such as blood thinners or heart rate management medicines may be given to those with AFib. Along with restoring a normal heartbeat, blood thinning medicine and other treatments may focus on fixing how hearts pump blood.

Heart Surgeries or Procedures

There are a variety of surgeries or procedures that can be vital to a patient with AFib, such as:

  • Cardiac surgery to insert a pacemaker
  • Left atrial appendage closure, a surgery to prevent blood clots in the upper chamber of the heart
  • Maze surgery to create a maze-like scar in the tissue of the heart

Nonsurgical Procedures

Some nonsurgical, less invasive procedures can work as well, including:

  • Catheter ablation, a non-surgical procedure that creates scar tissue
  • Electrical cardioversion, non-surgical shocks that restore a heart’s rhythm 

Lifestyle Changes

Primary care providers are likely to recommend lifestyle changes regardless because living a healthy life is key to longevity and long-term wellness. Certain changes may include:

  • Switching to a healthier diet
  • Maintaining a healthy weight
  • Limiting alcohol intake 
  • Stopping smoking
  • Reducing stress

These lifestyle changes can be used to prevent other heart diseases too. To live a heart-healthy life, explore these nine lifestyle habits. 


What causes a person to develop AFib?

There isn’t one cause of AFib. Instead, the condition can be caused by various cardiac and noncardiac conditions. Some of the most common include thyroid disorders, other heart diseases, and chronic lung diseases. While there are many potential causes, the reason is unknown in some cases. Because of Afib’s causal obscurity, it’s important to see your primary care provider regularly to discuss any health changes and receive necessary screenings, vaccinations, and more.

What are the most common triggers for AFib?

Specific factors can “trigger” AFib, including too much caffeine, dehydration, binge drinking, poor sleep, and stressful events. These factors can trigger atrial fibrillation for the first time or may cause additional heart flutters once someone is diagnosed with AFib.

How do you feel when you are in AFib?

Many people describe AFib as a fast or fluttering heartbeat. These quick and sometimes pounding palpitations are the most common sign of AFib. When someone experiences atrial fibrillation, they may also feel chest pain, dizziness, and fatigue.

Does drinking lots of water help with AFib?

Drinking water can help, especially if an electrolyte imbalance causes AFib. However, hydration alone isn’t enough to treat AFib. Those who are experiencing symptoms should consult a healthcare provider who can create a treatment plan with the right medicines, surgeries, procedures, and lifestyle changes.

What should you not do if you have atrial fibrillation?

If someone has atrial fibrillation, they should avoid smoking and excessive drinking. Eating a diet with less cholesterol, salt, and processed fats is also a good idea. Since caffeine can speed up the heart, limit how many coffees, energy drinks, and sodas someone consumes.


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