1.The room should be kept quiet and the room temperature should preferably be kept at about 20℃. 2, the subject should rest quietly for 5-15 minutes to eliminate the effects of tension and fatigue on blood pressure. 3, do not drink alcohol, coffee and strong tea, and to stop smoking. 4, the subject should be seated or supine, and the arm should be placed at the same level as the right atrium (the arm should be at the same level as the fourth rib cartilage when sitting, and at the mid-axillary level when lying down), and abducted 45 degrees. 5, before measuring blood pressure, the sphygmomanometer cuff should be emptied of gas, and then the cuff is tied flat to the upper arm, not too loose or too tight, so as not to affect the accuracy of the measured value. The lower edge of the cuff is 2 to 3 cm from the elbow socket. 6.A single high blood pressure cannot be diagnosed as hypertension 7.Differences in blood pressure between the left and right upper limbs, with a difference of 5 to 15 mmHg is normal. 8, do not be too concerned about the 5 ~ 10mmHg blood pressure fluctuations. 9, do not be nervous when measuring blood pressure, do not hold your breath, because holding your breath can make blood pressure rise. 10, measurement of blood pressure should try to achieve the four fixed, that is, fixed time, fixed site, fixed position (posture), fixed sphygmomanometer. Salt and hypertension: two silent killers!