Blood pressure is one of the vital signs that can be measured correctly to effectively develop a treatment plan. The correct measurement method is to adopt a lying or sitting position, and the patient should be quiet for at least 5 minutes, because measuring blood pressure immediately after exercise can also lead to an increase in error, then let the patient’s arm be at the level of the heart, the arm is too high or too low, it will affect the accuracy of the measurement, generally the arm is too high will lead to low blood pressure, the arm is too low will lead to high blood pressure, start winding the cuff, the cuff in the winding process should be moderately tight, to Too tight will lead to low blood pressure, too loose will lead to high blood pressure, the lower edge of the cuff from the elbow fossa above at least 2 cm, then the stethoscope close to the brachial artery, pumping pressure, the mercury column rise in the process of inaudible pulse, start to deflate the pulse of the first sound is the systolic pressure, the last sound is the diastolic pressure.