Before measurement, it is required to avoid strenuous sports or exercise, eating, drinking beverages (except water), especially those containing caffeine, taking medications that affect blood pressure, etc. 1 hour before measurement; 30 minutes before measurement, smoking should be stopped, the spirit relaxed, the bladder emptied, and at least 5 minutes of quiet rest should be taken before formal measurement. Before measurement, the mercury column of the sphygmomanometer should be at the vertical zero level, with the mercury column facing the surveyor, the subject exposing the right upper arm, the cuff should be tied flat and comfortably on the right upper arm, the tightness of which is appropriate to fit into the tips of two fingers, and the cuff air bag should wrap at least 80% of the upper arm, with the lower edge of the cuff placed at about 2-5 cm above the elbow fossa in front of the elbow joint, so that the inflated air bag is located exactly at the brachial artery pulsation site. The forearm when resting comfortably on the table, palm up, so that the height of the upper arm is approximately at the level of the heart Measurement procedure begins by squeezing the rubber bulb to inflate the cuff while touching the right brachial artery and noting the value of the height of the mercury column when the pulsation disappears. At this pressure, increase the pressure by another 30 mmHg, which is the maximum inflation level; then start measuring the blood pressure by placing the stethoscope tip under the cuff in the brachial artery area (usually slightly medial to the elbow fossa, i.e., the brachial artery can be found); after the uniform inflation is completed, watch the maximum inflation pressure, open the valve of the inflation ball, and keep the deflation rate constant so that the mercury column drops by about 2 mmHg/second. The cuff was gradually relaxed, and auscultation was performed throughout the deflation process. The first two consecutive blows are heard for systolic pressure and the last two consecutive blows are heard for diastolic pressure. After completion, the cuff is allowed to evacuate the gas and the readings are recorded.