Researchers from Mount Sinai Hospital in Toronto, Canada (Mount Sinai Hospital) pointed out through a study that people with high blood pressure who sleep less than five hours or more than eight hours per night may have a higher risk of stroke. In the study, researchers collected data from the National Health Interview Survey of nearly 204,000 people with hypertension over nine years, and said that overall the risk of stroke was 14 percent in individuals who slept longer, 11 percent in individuals who did not get enough sleep, 6 percent in individuals who slept 5-6 hours a night, and 5 percent in healthy individuals. The risk of stroke was 5 percent for healthy individuals. Researchers believe that too little sleep can easily cause the body to increase the concentration of cortisone, a “stress hormone”, which may be the reason for the increased risk of stroke. The longer sleep time may be related to the body’s secretion of inflammatory chemicals. Under normal circumstances, a person’s blood pressure at night is lower than daytime levels, but lack of sleep or poor sleep quality can cause an increase in blood pressure levels at night, mainly due to abnormally high sympathetic excitability, and can also lead to an early morning blood pressure peak, which then affects blood pressure throughout the day. The abnormal fluctuation of blood pressure will in turn affect the quality of sleep, forming a vicious circle. Thus, hypertensive patients need to pay attention to the length of sleep, whether too much sleep, too little sleep is not good, while improving the quality of sleep is also a remedy to stabilize blood pressure.