For nearly a decade, UK researchers tracked the sleeping habits and stroke rates of nearly 10,000 middle-aged and older adults. Those who slept more than 8 hours a night were 46% more likely to suffer a stroke than those who slept between 6 and 8 hours. MORE: 8 Things Your Sleep Habits Say About You More frightening: People who slept fewer than 6 nightly hours at the start of the study—but later shifted to 8-plus hours—were nearly 4 times more likely to suffer a stroke than people with steady sleep habits. The study authors are quick to point out that “long sleep” (as they define as sleeping more than 8 hours) probably doesn’t cause strokes. Just as smoke signals fire but doesn’t cause it, it’s likely sleeping more than 8 hours is a sign something’s amiss with your health, says study coauthor Yue Leng, a public health researcher at the University of Cambridge. A big jump in sleep time may be a sign your health is declining, Leng explains. Changes in the way blood flows in your brain could also explain both a shift in your sleep habits and an increased risk for stroke. Despite these sleep-stroke connections, Leng says everybody’s nighttime habits are different. “Sleeping for more than 8 hours does not always mean elevated stroke risk, particularly for young people who are healthy otherwise,” Leng adds. Meaning, don’t freak out just because you enjoy a lot of sack time. But if you’re sleeping more than 8 hours, it’s a good idea to notify your doctor and keep tabs on other markers of stroke risk—like blood pressure and cholesterol, says the University of Miami’s Alberto Ramos, MD, in a Neurology editorial about the UK stroke study. That’s especially true for older adults who notice a big shift in their sleep habits. MORE: Scary Signs Sleep Loss Is Messing With Your Mind
