The curve of normal blood pressure is spoon shaped, there are 2 peaks and a trough, 8-10 am is the highest blood pressure in a day and the first peak, 4-6 pm is the 2nd peak and 1-2 pm is the trough of blood pressure. For patients with hypertension, most of the highest blood pressure is at the first peak in the morning, between 8-10 a.m., called the morning peak phenomenon of hypertension. Some patients with hypertension do not have a normal spoon-shaped curve and have a non-spoon-shaped curve, his highest blood pressure can be at other times of the day, some can be in the afternoon, and some can even have an anti-spoon-shaped curve at night, which is a time when the highest peak of blood pressure can be very harmful to clinical events.