Each measurement of blood pressure is different, and in order to avoid errors during the physical examination, at least two measurements should be taken, whichever is lower. In standard circumstances, blood pressure should be measured in a quiet and resting state, and the blood pressure in the brachial artery of the right upper limb is usually measured. It should be measured at least twice, whichever is lower. Generally speaking, the difference between the blood pressure measurements of the right and left upper arms is <10~20mmHg, if the difference is large, it suggests that there may be an obstructive lesion of one side of the subclavian artery and the distal end of the subclavian artery, and then you should go to the hospital in time to make a clear diagnosis. It should be noted that, to determine whether the blood pressure is elevated, based solely on one or two clinic blood pressure measurements is unscientific, and it is necessary to observe and assess the changes in blood pressure and the overall level of blood pressure through a period of follow-up. For hypertensive patients, it is necessary to make full use of home self-measurement of blood pressure and ambulatory blood pressure to assess the status of blood pressure in order to control blood pressure more effectively.