What Triggers Atrial Fibrillation?

Medically Reviewed by Zilpah Sheikh, MD on February 29, 2024
7 min read

Atrial fibrillation (AFib) is the most common problem with your heartbeat's rate or rhythm.

Your heart has four chambers – two upper chambers called atria and two lower called ventricles. Inside the upper right chamber of your heart, you have a group of cells called the sinus node, which creates the signals to start each heartbeat. Those signals move across the upper parts of your heart and reach another node, called the atrioventricular (AV) node. From there, the signals travel to the lower chambers of your heart.

The basic cause of AFib is disorganized signals that cause the atria of your heart to squeeze very fast and out of sync. They contract so quickly that the heart walls quiver, or fibrillate. The AV node is overwhelmed with signals.

A normal resting heart rate is about 60-100 beats a minute. When you're in Afib, your heart might beat 100-175 times per minute.

Damage to your heart's electrical system can cause AFib. This damage often results from other conditions that affect the heart. But in at least 1 of every 10 AFib cases, other things may be at play. Sometimes, doctors can't figure out what's causing AFib.

Even after the condition has been diagnosed, you may be able to control your AFib and avoid such episodes if you know your triggers.

Can low potassium cause AFib?

Researchers have found that low potassium levels in your body are linked to an increased risk of AFib. Low potassium, also called hypokalemia, has many causes. A common reason for hypokalemia is losing too much potassium in your pee because of certain medications you take. Diuretics, which increase urination, can cause this. They're often prescribed for people with high blood pressure or heart disease.

Can dehydration cause AFib?

Dehydration is a common trigger for an AFib episode, but it isn't the cause of your AFib. It's simply something that can set off your symptoms.

Things that most often lead to atrial fibrillation include:

Age: Your odds of having AFib go up as you get older, especially after you're 60. In part, that’s because you’re more likely to get heart disease and other conditions that can cause AFib.

Genes: AFib is a hereditary condition, which means a part of the cause is in the genes you get from your parents at birth. If someone in your close family had or has it, there's a greater risk for you, too.

Ethnicity: People of European descent have a higher rate of AFib than those of Black, Hispanic, or Asian ancestry. However, research shows differences in the way AFib is treated in Black people. They also have more complications, and their death rate from AFib is higher.

Gender: Among people with European ancestry, those assigned female at birth are more likely to have AFib than those assigned male at birth. There are also differences in the treatment they receive, and their rates of complications and death from AFib are higher.

Heart disease: AFib is a problem with your heart. So, other heart issues raise your chances of having it, such as:

Heart conditions such as these raise your chances for AFib because they create physical stress and stretch the tissues in the upper left chamber of the heart, says Ayman Hussein, MD, co-director of the Atrial Fibrillation Center at Cleveland Clinic. The stress and stretching lead to changes in cellular electrical properties and heart structure (like the upper chamber getting larger and more scarred). The combination of these things can make you more likely to have AFib.

If you have AFib and another heart condition, get treatment as soon as possible.

Sick sinus syndrome: This isn’t the same as the sinuses in your head; it refers to the sinus node in your heart. Think of it as your heart’s own natural pacemaker. Sinus node problems that can lead to AFib include:

  • Misfiring of your heart's electrical signals
  • Fluctuating heart rate (alternating between fast and slow)

Heart attack: When the artery that supplies blood to the atria is blocked, it can damage atrial tissue and lead to AFib.

But AFib doesn’t generally cause heart attacks unless the heart rate is fast and puts the heart under stress.

Heart surgery: AFib is the most common complication. It will happen to 2 or 3 out of every 10 people recovering from a heart operation.

High blood pressure: It’s the most common condition linked to AFib. It can make the atria (the upper chambers of your heart) get bigger, which makes it work harder.

Lung disease: This includes chronic obstructive pulmonary disease (COPD), emphysema, or a blood clot in your lung (pulmonary embolism). COPD in particular often comes along with high blood pressure, heart disease, ventricle problems, and other problems that play a role in AFib, such as:

  • Low blood oxygen and high carbon dioxide levels
  • Cigarette smoking
  • Cardiac autonomic dysfunction -- your autonomic nervous system controls your heartbeat. In lung disease, it can get out of whack.
  • Inhaled medications that boost your heart rate

An overactive thyroid gland (hyperthyroidism): It speeds up everything in your body, including your heart.

Obesity, diabetes, and metabolic syndrome: These conditions are not only linked to hypertension but may also make it harder for your heart to empty. And they cause other physical changes that raise your risk of AFib.

Sleep apnea: Each time you are suddenly awakened due to a lack of oxygen, it puts mechanical stress on your heart and causes chemical changes. Plus, over time, sleep apnea can lead to conditions such as high blood pressure and obesity, which make AFib more likely.

Infections caused by a virus: The resulting inflammation could cause changes to your heart.

Changes in body mineral levels: Potassium isn't the only mineral that can affect AFib. If your levels of sodium, calcium, or magnesium are too high or too low, that can raise your AFib risk.

Medication: Research suggests that people who take high doses of steroids -- perhaps for asthma or other conditions -- may be more likely to get AFib. If your chances are higher anyway, this treatment can trigger an episode. So can over-the-counter cold medications with caffeine or other ingredients that speed up your heart rate.

No clear cause: Sometimes, doctors can’t find an obvious reason why someone gets AFib. There’s an upside when this happens in people under 65 years who don’t have health conditions linked to AFib. Their chances of getting blood clots and strokes are a lot lower than people who are older or who have clear causes for AFib.

You may notice that certain things cause your AFib symptoms to flare up. Some common triggers are:

  • Stimulants: Caffeine, cigarettes, and other things that speed up your system can set off AFib. Caffeine will probably affect you more if you don't usually drink it.
  • Alcohol: For some people, binge drinking is a trigger. But for others, even a modest amount can trigger AFib.
  • Stress and worry: When you're under a lot of pressure or feeling worn out, it could trigger an episode or worsen your symptoms.
  • Strenuous exercise: A workout that raises your heart rate above a certain point (but it’s still important to get exercise) can also be an AFib trigger.
  • Poor sleep or sleep apnea


Some AFib risk factors, such as age and genetics, are out of your control. But a healthy lifestyle can help guard against AFib and other types of heart disease. Some steps you can take:

Atrial fibrillation – also called AFib – is a problem with the way your heart's chambers send signals that control its beat. Many things can increase your risk for AFib, including age, family history, heart disease, heart surgery, high blood pressure, and obesity. An AFib episode can be triggered by dehydration, lack of sleep, stress, and stimulants such as caffeine.

Can atrial fibrillation go away?

If you have a type called paroxysmal AFib, it might go away on its own. This kind of AFib usually lasts less than a week. But paroxysmal AFib can progress to the persistent type (lasting more than a week) or long-standing AFib (lasting more than a year). It all depends on your risk factors. If you develop persistent or long-standing AFib, you'll need treatment. Because AFib can lead to a stroke, you should talk to your doctor about the best way to manage your symptoms.

Can you live a long life with atrial fibrillation?

AFib by itself isn't fatal. Earlier diagnoses and better treatments over the last few decades have improved the outlook for those with AFib. Every case is different, but research suggests that on average, AFib shortens your life by about 2 years.

Can anxiety cause atrial fibrillation?

Experts don't fully understand the relationship between anxiety and AFib. There's just not enough research to say for sure whether anxiety disorders raise your risk of AFib. However, having AFib can indeed cause anxiety, as you may worry about triggering your AFib or how your symptoms affect your life.

What should you not do with atrial fibrillation?

If you have AFib, it's important to maintain a healthy lifestyle, including exercise. But pushing your heart too hard during a workout can trigger an episode. Talk to your doctor about your target heart rate during exercise and the best way to achieve it. Monitor your heart as you work out. Limit how much alcohol and caffeine you drink because they can dehydrate you. Recreational drugs and herbal supplements can raise your heart rate and interfere with your medication. Talk to your doctor before you use any supplements. Over-the-counter medicines for pain, colds, and flu also can affect your heart. Avoid nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen. You should also avoid decongestants that contain pseudoephedrine or phenylephrine.