Researchers surveyed nearly 4,500 individuals across the globe, about half of whom had experienced a stroke and about half who had not. The average age of participants was 62. 

People who got less than five hours of sleep each night were three times more likely to have had a stroke than those who got the recommended minimum of seven hours for adults. Those who got more than nine hours of sleep were also twice as likely to have a stroke, researchers found.

What’s more, those who napped for longer than an hour were nearly 90% more likely to have a stroke than those who napped less than an hour.

Researchers also noticed a connection between breathing issues during sleep and stroke risk. Those who snored were 91% more likely to have a stroke than those who didn’t, and people who snorted or had sleep apnea were nearly three times more likely to have a stroke.

Sleep-related risk factors that may increase your stroke risk

People with five or more of the following symptoms may be at a five-times-greater risk of stroke, according to researchers:

• Snoring while sleeping
• Snorting while sleeping
• Sleep apnea
• Poor-quality sleep
• Taking long naps
• Sleeping too little
• Sleeping too much

Christine McCarthy, a researcher in the department of geriatrics at the University of Galway in Ireland and one of the study’s authors, says she hopes the findings spur doctors to discuss stroke risk with their patients who have sleeping issues.

“Our results suggest that sleep problems should be an area of focus for stroke prevention,” she said in a release about the study.

Tips for getting a better night’s rest

If you see yourself in these risk factors, there are things you can do that will likely improve your sleep, experts say. Aside from seeking treatment if you suspect you have sleep apnea, the U.S. Centers for Disease Control and Prevention recommends taking the following steps:

• Set a consistent bedtime and wake time. Stick to it, even on weekends.
• Ensure that your bedroom is dark, quiet, and at a comfortable temperature.
• Remove all electronics from the bedroom. That includes TVs, computers, and smartphones.

The experts at Harvard University’s Division of Sleep Medicine offer a few additional tips, including these:

• Avoid using stimulants like caffeine, alcohol, or nicotine within a four-to six-hour window before bedtime.
• If you’re going to nap, keep it short, and ensure it’s before 5 p.m.
• Don’t eat too close to bedtime. If you do, avoid foods that will give you indigestion.
• Drink enough liquids before going to bed so that you don’t wake up thirsty, but not so much that you must wake up to use the bathroom.
• Be sure to exercise, but do so at least three hours before bedtime. Exercise can improve sleep quality, but it also stimulates the release of the stress hormone cortisol, which keeps people awake.

Do you have a sleep disorder?

If you have excessive daytime sleepiness despite efforts to optimize your nighttime routine, you may be one of the tens of millions of Americans with a sleep disorder. Consider taking Harvard’s sleep disorders screening survey here, and contact your primary care doctor for help.