Key takeaways:
Atrial fibrillation (AFib) is a heart rhythm problem that becomes more common with age. It causes an erratic heartbeat that’s often faster than normal.
It’s not always clear what causes AFib. But risk factors include family history, smoking, alcohol use, and medical problems like high blood pressure and diabetes.
If you have AFib, you can prevent it from getting worse by avoiding common triggers and following a heart-healthy lifestyle.
Atrial fibrillation (AFib) is the most common type of abnormal heart rhythm in the U.S. It happens when your heart’s upper chambers (the atria) beat fast and irregularly. But even though AFib is a heart problem, it can be caused by many different conditions in your body — both inside and outside of your heart. Also, what causes someone to develop AFib may be different from what triggers episodes after they already have the condition.
In this article, we’ll review the causes, triggers, and risk factors for AFib. But before we dive in, it may help to define how these three terms differ:
Causes are the direct reasons someone develops AFib, such as heart disease. But not everyone with AFib has a clear or identifiable cause.
Triggers are circumstances that can lead to an episode of AFib, such as dehydration. They aren’t the underlying cause, but can be what unmasks the condition.
Risk factors are things that increase a person’s likelihood of developing AFib during their lifetime, such as genetics.
What causes atrial fibrillation (AFib)?
Atrial fibrillation (AFib) is caused by changes in the heart’s electrical system. These changes can be caused by other heart problems, such as:
High blood pressure
Heart failure
Coronary artery disease or previous heart attacks
Heart valve problems
Congenital heart disease
But not everyone with AFib has an underlying heart condition. And not everyone with AFib has a clear cause. Like many health conditions, AFib is often caused by the combination of genetics and environmental factors. We’ll discuss these risk factors later in the article.
How AFib develops
The heartbeat is controlled by an electrical circuit that starts at something called the sinus node. The sinus node sits at the top of your heart. Each time the sinus note generates an electrical impulse, it travels through the upper chambers of your heart (the atria), down into the lower chambers (the ventricles). This results in a coordinated contraction of the heart muscle that pumps blood throughout your body.
For example, when your heart beats at 60 beats per minute, this is because the sinus node is generating 60 electrical impulses per minute.
AFib develops when the sinus node loses control of your heartbeat and disorganized electrical signals in your atria take over. These signals interfere with the organized beat of your sinus node causing your heartbeat to become erratic and often faster than normal.
Types of AFib
There are different types of AFib based on how long episodes last:
Paroxysmal: This is AFib that comes and goes and stops on its own within 7 days.
Persistent: This is AFib that lasts for more than 7 days. Treatment is usually needed to get your heart back into a normal rhythm.
Long-term persistent: This is when AFib has lasted for more than 12 months.
Permanent: This is when the AFib doesn’t go away with treatment, so the heart rhythm remains in AFib.
It’s important to note that AFib can also change over time. For example, someone with paroxysmal AFib may later develop persistent AFib.
What triggers atrial fibrillation?
There are common triggers for AFib that can make episodes more likely to happen. Triggers are different for everyone, and not everyone with AFib can identify triggers. Still, it can be helpful to pay attention to how your heart responds to changes in your body and environment.
Medical triggers
Anything that stresses your body or throws it out of balance can be a trigger for AFib. Some common examples include:
Surgery
Infection
Thyroid disease
Dehydration or electrolyte changes
Any illness that affects your heart or lungs
Lifestyle triggers
Lifestyle factors that can trigger AFib include:
Tobacco or nicotine use
Stimulants like caffeine, especially from energy drinks
Emotional stress
Overexertion
Poor sleep
What are the risk factors for atrial fibrillation?
There’s a lot of overlap between AFib triggers and risk factors, but they’re not the same thing. While a trigger is something that can bring on an episode of AFib, a risk factor is something that increases your chance of developing it in the first place.
For example, regular heavy alcohol use can increase your risk for developing AFib over time. But someone who already has AFib can trigger an episode with a single night of drinking.
Age
The risk of AFib increases as you get older. The following numbers from a research study can help you get a sense of how risk increases over time.
Age | Percentage of people with AFib |
|---|---|
Under 50 | Less than 1% (1 in 385 people) |
50-59 | Almost 2% (1 in 65 people) |
60-69 | About 4% (1 in 25 people) |
70-79 | About 9% (1 in 11 people) |
80-89 | About 20% (1 in 5 people) |
90 and older | 25% (1 in 4 people) |
Genetics
AFib can be hereditary. Researchers have identified many different genes that can increase a person’s risk. AFib also seems to be more common in people of European ancestry. But people of all racial and ethnic backgrounds can get AFib. And having a family history of AFib doesn’t mean you’ll get it.
Lifestyle risk factors
Many of the lifestyle factors that can trigger AFib can also increase your risk for developing it, including:
Smoking
Alcohol use
Stress
Medical risk factors
Long-term medical conditions can also increase your risk of AFib, including:
Excess weight
Heart disease
An overactive thyroid gland
Chronic obstructive pulmonary disease (COPD)
How can you prevent atrial fibrillation from getting worse?
If you have AFib, there’s a lot you can do to prevent it from getting worse. A healthy lifestyle is part of treating and preventing AFib and its complications. This can include:
Cutting back on or quitting smoking
Limiting alcohol intake
Treating high blood pressure, diabetes, heart failure, and sleep apnea
Maintaining a healthy weight
Getting regular physical activity
Following a heart-healthy diet
These things are important, but they shouldn’t replace your treatment plan. It’s also important to take your daily medications and follow up with your healthcare team as recommended.
But even if you do everything right, your heart still may go into AFib. This doesn’t mean you have done anything wrong, so don’t be hard on yourself.
Frequently asked questions
Common symptoms of atrial fibrillation (AFib) include:
Palpitations, or a fluttering in your chest
Lightheadedness or dizziness
Fatigue or overall weakness
Chest pain
Shortness of breath or feeling easily winded with light exertion
AFib can lead to serious health problems, such as:
Stroke: AFib increases the risk of a blood clot forming in your heart. These clots can move to other parts of your body like your brain and cause a stroke.
Heart failure: AFib can increase the risk of heart failure because it puts stress on your heart. This is particularly true when AFib causes a rapid heart rate.
Heart attacks: If a blood clot forms inside your heart, it can travel to the heart’s blood vessels (the coronary arteries), causing a heart attack.
The right AFib treatment can help prevent these serious problems from happening.
The most common treatments for AFib include:
Medications that help control your heart rhythm and/or heart rate
Blood thinners to lower your risk of stroke
Heart ablation, a catheter-based procedure that targets the parts of your heart that cause abnormal electrical impulses
But there are many treatments — both medications and procedures — that can help treat AFib.
If you’re experiencing AFib, talk with your healthcare team. AFib can vary in severity, and some complications may need treatment in a hospital. But over the long term, AFib can be managed in an outpatient clinic.
General practitioners often treat AFib, but more complex cases may need the expertise of a cardiologist. An electrophysiologist is a specialized cardiologist who treats abnormal heart rhythms like AFib.
Common symptoms of atrial fibrillation (AFib) include:
Palpitations, or a fluttering in your chest
Lightheadedness or dizziness
Fatigue or overall weakness
Chest pain
Shortness of breath or feeling easily winded with light exertion
AFib can lead to serious health problems, such as:
Stroke: AFib increases the risk of a blood clot forming in your heart. These clots can move to other parts of your body like your brain and cause a stroke.
Heart failure: AFib can increase the risk of heart failure because it puts stress on your heart. This is particularly true when AFib causes a rapid heart rate.
Heart attacks: If a blood clot forms inside your heart, it can travel to the heart’s blood vessels (the coronary arteries), causing a heart attack.
The right AFib treatment can help prevent these serious problems from happening.
The most common treatments for AFib include:
Medications that help control your heart rhythm and/or heart rate
Blood thinners to lower your risk of stroke
Heart ablation, a catheter-based procedure that targets the parts of your heart that cause abnormal electrical impulses
But there are many treatments — both medications and procedures — that can help treat AFib.
If you’re experiencing AFib, talk with your healthcare team. AFib can vary in severity, and some complications may need treatment in a hospital. But over the long term, AFib can be managed in an outpatient clinic.
General practitioners often treat AFib, but more complex cases may need the expertise of a cardiologist. An electrophysiologist is a specialized cardiologist who treats abnormal heart rhythms like AFib.
The bottom line
Atrial fibrillation (AFib) is a common abnormal heart rhythm. It can have many different causes and triggers, and AFib can affect each person differently. This also means that there’s a lot you can do to prevent AFib from happening or getting worse. Simple strategies such as getting a good night’s sleep, eating a heart-healthy diet, and following up with regular healthcare visits can make a difference. With the right lifestyle changes and treatments, AFib is a very treatable condition.
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References
Chung, M. K., et al. (2020). Lifestyle and risk factor modification for reduction of atrial fibrillation: A scientific statement from the American Heart Association. Circulation.
Hansson, A., et al. (2004). Arrhythmia-provoking factors and symptoms at the onset of paroxysmal atrial fibrillation: A study based on interviews with 100 patients seeking hospital assistance. BMC Cardiovascular Disorders.
Mattioli, V. (2014). Beverages of daily life: Impact of caffeine on atrial fibrillation. Journal of Atrial Fibrillation.
National Heart, Lung, and Blood Institute. (2022). Atrial fibrillation type.
Oltman, C. G., et al. (2024). Prevalence, management, and comorbidities of adults with atrial fibrillation in the United States, 2019 to 2023. JACC Advances.
U.S. Centers for Disease Control and Prevention. (2024). About atrial fibrillation.
Weng, L. C., et al. (2017). Heritability of atrial fibrillation. Circulation Cardiovascular Genetics.
