Before starting the sphygmomanometer, check it first. The dial of the sphygmomanometer that can be used normally usually refers to the "0" position. After pressurization, it reacts flexibly and can still return to the original "0" position.

The blood pressure range of normal adults in quiet state is relatively stable, with systolic blood pressure of 90 ~ 139mmhg, diastolic blood pressure of 60 ~ 89mmhg and pulse pressure of 30 ~ 40mmhg.

Blood pressure should be measured when the patient is resting quietly. If the patient is exercising, or smoking or has emotional fluctuation, the blood pressure should be measured after resting for 30 minutes.