The people they face insomnia, difficulty sleeping or waking up too early they may have more likely to have a stroke, according to a study published in the online issue of the Journal of the American Academy of Neurology, Neurology.

The study involved 31,126 people with an average age of 61 who had no history of stroke at the start of the study. Participants were asked to answer four questions about how often they had trouble falling asleep, how often they woke up too early and couldn’t get back to sleep, and how often they felt rested in the morning. The scores given to the responses ranged from zero to eight, with higher scores corresponding to more severe symptoms.

The participants were then followed for nine years, and during that time there were 2,101 cases of stroke. The researchers found that people with one to four symptoms had a 16% increased risk of stroke compared to people with no symptoms. People with five to eight insomnia symptoms had a 51% increased risk.

The researchers found that the risk was much higher in people under the age of 50, with those with five to eight symptoms having almost four times the risk of stroke compared to people with no symptoms. The association also increased further for people with diabetes, hypertension, heart disease and depression.