Over 2 million Americans have atrial fibrillation, or A-fib, a heart condition that causes the heart to pump erratically and inefficiently. Normally, the steady beat of the heart pumps blood throughout the body. A-fib causes the upper chambers of the heart to quiver, rather than contract steadily. So someone with A-fib may experience rapid heart rate, dizziness, and shortness of breath. A-fib increases the risk of heart failure because the heart is working ineffectively. It also increases the risk of stroke because A-fib allows blood to pool in the heart, where it might clot. If a subsequent heartbeat delivers the clot to the brain, it might block a blood vessel and cause a stroke.

But what causes A-fib?

Most researchers and scientists think afib is related to a variety of factors. Some—like your genetic history—can’t be changed. Others, such as high blood pressure or alcohol intake, can be modified to decrease your risk of developing A-fib.

Unmodifiable Risk Factors

  • Genetics.  Approximately 30 percent of all A-fib cases have a genetic link. At least two genetic mutations are now known to increase the risk of A-fib. While you can’t do anything to change your genetics – and a genetic intervention is a long, long way off – being aware of your family history can help your doctor plan appropriate tests and interventions. If there’s a history of A-fib or heart disease in your family, be sure to let your doctor know.
  • Age.   Afib affects approximately one percent of the general population. But by age 80, 10 percent of people develop A-fib.
  • Sex.  Men are more likely to develop afib, but women are more likely to die from it.
  • Congenital heart defects.  Some people are born with defects of the heart. If you have an abnormal heart valve, sick sinus syndrome (a disorder that affects the electrical activity of the heart) or were born with a structural defect of your heart, you’re more likely to develop A-fib.
  • History of heart disease.  If you’ve already suffered a heart attack or undergone heart surgery, you’re more likely to develop afib. The good news is that your doctor is aware of this increased risk, and will be monitoring your heart carefully.

Modifiable Risk Factors

  • High blood pressure.  True, some people are genetically predisposed to developing high blood pressure. But you can take steps to control your blood pressure. A-fib is more likely to occur in someone with uncontrolled (or poorly controlled) high blood pressure, so be sure to take any prescription blood pressure meds as prescribed.
  • Thyroid problems.  An overactive thyroid is known to increase the risk of A-fib. If you have a family history of thyroid disease, have your doctor check your thyroid hormone levels. Taking medication can help control an overactive thyroid.
  • Exposure to stimulants.  Caffeine, alcohol, tobacco, and recreational drugs have all been linked to an increased risk of afib. So if you want to decrease your risk, avoid recreational drugs and tobacco, and use caffeine and alcohol in moderation. Limiting stimulant intake may be particularly important if you have a number of unmodifiable risk factors.
  • Sleep apnea.  About half of all people with A-fib also have obstructive sleep apnea, a sleep disorder that interferes with the delivery of oxygen to the heart and brain in the night. Snoring and pauses of breath during the night are common symptoms of sleep apnea. Constant daytime drowsiness is another symptom. If you have any of these symptoms, tell your physician. He may order a sleep study to check for the presence of sleep apnea. If apnea is present, a variety of treatments are available to help improve nighttime breathing and oxygen flow. Treating sleep apnea is known to decrease the risk of heart disease.
  • Stress.  Some patients and doctors believe that extreme stress triggers episodes of afib. Controlling your stress through relaxation, exercise, or distraction may help decrease your chances of experiencing A-fib.