Sleep and hypertension
People suffering from hypertension who lie awake at night may be at a greater risk of heart damage than those who sleep through the night. Researchers at the University of Pavia in Italy examined the effect of lack of sleep on blood pressure and heart rate. They monitored 36 people with high blood pressure, who had never been treated, during the night. The patients were observed from 3 am to 7 am and again after a week when they slept from 11 pm to seven am. The researchers noticed a distinct rise in blood pressure and heart rate during the period when they were deprived of sleep. After the sleepless night, the blood pressure and heart rate were higher until the next noon than during the morning after a full night's sleep (American Journal of Hypertension Vol 17, No1).