Too much sleep is linked to stroke risk
Getting too much sleep can increase the risk of having a stroke, scientists have said.
A study by the University of Cambridge shows the risk doubles for older people who persistently sleep longer than the average eight hours a night.
For those whose sleep patterns increased from short to long over time, the risk was close to four times that of people who maintained an average sleep pattern.
"It's apparent both from our own participants and the wealth of international data that there's a link between sleeping longer than average and a greater risk of stroke," said researcher Yue Leng.
"What is far less clear, however, is the direction of this link, whether longer sleep is a symptom, an early marker or a cause of cardiovascular problems."
Researchers from the university's Department of Public Health followed almost 10,000 people aged 42 to 81 over almost 10 years.
Most reported sleeping between six and eight hours a day, while one in 10 said they slept for more than eight hours a day.
Over the course of the study, 346 participants suffered a stroke and, after taking into account other factors, the team concluded that people who slept longer than eight hours a day were at 46pc greater risk of stroke than average.
The risk doubled for those who reported persistently long sleep over the entire course of the study.