Blood pressure: sleep

It’s wise to pay attention to your blood pressure -- but don’t lose sleep over it. That may make matters worse. A five-year study published last year found that among nearly 600 adults (average age 40 at the start of the study) the fewer hours of sleep people got, the higher their blood pressure was likely to be and the more likely it was that their blood pressure would increase over time. For every hour less sleep participants got, their chances of developing high blood pressure over the study period zoomed up by 37%.

Another study of more than 10,000 adults ages 35 to 55 found that women who averaged six hours of sleep a night were 42% more likely to develop high blood pressure than women who averaged seven hours -- though it found no such effect for men. A 2006 study reported a similar finding for both genders: Of those who slept five hours a night or less, 24% developed high blood pressure during eight to 10 years of follow-up, versus 12% of those who slept seven or eight hours.

The reasons for this effect of sleep aren’t clear, although it is known that blood pressure typically drops during sleep and thus brings down the average blood pressure for the day.