People with atrial fibrillation (AFib) may have a higher risk of having a stroke. Doctors may recommend blood thinners to lower this risk. Medical care is essential.

AFib is an irregular heartbeat that affects the upper chambers of your heart, which are called the atria.

Several conditions may increase your risk of AFib, including:

  • heart valve disease
  • high blood pressure
  • congenital heart disease
  • buildup of plaque in your blood vessels (atherosclerosis)

A stroke occurs when blood flow to an area of your brain is disrupted. A ruptured blood vessel or an obstruction, often caused by a blood clot, can reduce blood flow.

AFib can cause blood flow through your atrium to slow down. This slowing of blood flow can cause blood clots that can lead to a stroke if they block blood vessels in a region of your brain.

AFib is a well-established risk factor for the development of a stroke. The pooling of blood in the upper chambers of your heart increases the risk of a blood clot.

Blood clots can travel through your bloodstream and cause a blockage in a blood vessel serving an area of your brain. When this happens, it’s called an ischemic stroke.

Because AFib and stroke share other risk factors, people with AFib have a higher risk of stroke than those who don’t have AFib. The chance of a stroke may be higher right after a long AFib episode.

In a 2021 study of people with cardiac implantable electronic devices who had AFib episodes for longer than 5 and a half hours, researchers found that the risk of having a stroke was highest within 5 days of the episode. The risk sharply declined after this period.

In a 2024 review of studies, researchers also found that the risk of having a stroke was highest in the 5 days after an AFib event and that it tapered off over about 10 to 20 days.

AFib is associated with an elevated risk of ischemic stroke. An ischemic stroke is when a blood clot or another substance blocks a blood vessel in your brain. Ischemic strokes are the most common type of stroke, making up about 87% of cases in the United States.

According to the Centers for Disease Control and Prevention (CDC), strokes associated with AFib tend to be more severe than strokes with other underlying causes.

Treating AFib is an effective way of reducing the chance of AFib-related strokes. Your treatment may consist of a combination of:

Lifestyle changes

Lifestyle changes that a healthcare professional may recommend for AFib include:

  • maintaining or getting to the body weight recommended for your age and height
  • limiting or avoiding alcohol and other stimulant substances
  • exercising regularly
  • quitting smoking, if you use tobacco
  • eating a heart-healthy diet, like the DASH diet

Medications

Medications that a doctor may prescribe to help treat AFib include:

Procedures

Medical procedures for treating AFib include:

  • electrical cardioversion to restore your heart rhythm with low energy shocks
  • catheter ablation, which involves threading a long tube through your bloodstream to your heart to apply an electrical pulse with an electrode
  • pacemaker implantation to speed up your heart rate and prevent AFib due to a slow heart rate
  • left atrial appendage closure to close off a small sac in the wall of your left atrium
  • maze procedure to temporarily stop your heart while a surgeon makes a series of cuts that produce scar tissue around your atria

How long after an AFib episode are you at risk of stroke?

The risk of ischemic stroke seems to be highest 3 to 5 days after an AFib episode. Doctor-supervised use of blood thinners may lower this risk.

How long does the average person live with AFib?

In a Danish study from 2022, researchers found that people with heart failure lost an average of 1.5 years of life expectancy over a 10-year follow-up period after AFib diagnosis.

In people with no history of heart failure, AFib may decrease life expectancy depending on different factors, such as their age and overall health status. You may want to talk with a healthcare professional about different ways to lower your risk of complications.

Does drinking lots of water help with AFib?

Drinking water may help with AFib if you’re dehydrated. Dehydration leads to electrolyte imbalance, which increases the risk of AFib and other heart arrhythmias. Drinking 6 to 8 glasses of water every day may help maintain hydration levels, though it depends on your activity and water loss levels.

It’s essential to seek emergency medical attention if you develop symptoms of a stroke. These stroke symptoms include sudden:

  • numbness or weakness on one side of your face or in one arm or leg
  • unexplained mental confusion
  • trouble seeing
  • trouble walking or coordinating movements
  • severe headache with no obvious cause

AFib significantly increases your risk of having an ischemic stroke. The increased risk largely comes from the higher chance of developing blood clots that may cause a blockage in a blood vessel supplying an area of your brain.

The best way to prevent AFib-related strokes is by treating the underlying cause of your AFib. Treatment often includes a combination of lifestyle changes and medications. It may also involve surgery or treatment for an underlying condition.