Getting a solid 7-8 hours of sleep at night is vital for a healthy life. A new study confirms that, reporting that missing out on sleep or oversleeping severely increases the chance of a stroke.

Photo by Aweisenfels.

Researchers conducted an analysis of the health of 288,888 adults (77 percent white; nearly half 45 or older) who participated in a survey from 2004 to 2013. They analyzed the health, lifestyle and demographics as well as how much they slept on average and whether they worked out or conducted physical activities (long walks, swimming, gardening).

The main findings were not surprising at first. People who got proper sleep, 7-8 hours a night were 25 percent less likely to have experienced a stroke. Short sleepers, who slept under 7 hours were 22 percent more likely to suffer a stroke. However the big surprise came for over-sleepers: people who got over 8 hours a sleep were 146 percent more likely to have suffered a stroke!

It’s not clear exactly how the causality goes in here – whether one causes the other, whether something else causes both or if the two are not correlated but overs-sleepers apparently have a much larger chance to get a stroke.

Authors also argue that computer analysis of large, complex health information sets is an important tool for accurately determining health risks in populations and finding unexpected connections such as this one.

Overall, it’s difficult to quantify how lifestyle affects the chance of a stroke, but one thing’s clear: there’s no substitute for good quality sleep