The best time of day to take a reading is just before you go to bed. Why? Well, it’s been shown that the average person will have their blood pressure rise by as much as 30 points overnight from being awake for too long and not getting enough sleep. In fact, if your blood pressure continues to climb over night, it can be a sign that high stress or anxiety might be causing this increase in pressure. These things are actually quite common among people who suffer with high blood pressure so try taking your reading at bedtime each night and see if there is any change!