It is important to know the correct way to measure blood pressure to control it. In my clinical work, I have met some friends suffering from hypertension who have asked me about the method of measuring blood pressure, and there are many patients who have measured it themselves who have used methods that are not scientific enough. Today, I will introduce you to the scientific method of measuring blood pressure. (Take the mercury column sphygmomanometer as an example). First of all, when measuring blood pressure, you should choose a suitable position, take a sitting or supine position, so that the measured limb and the heart are at the same level. Roll up the cuff and expose the arm with the palm up and the elbow straight, place the sphygmomanometer in a stable position, and turn on the mercury tank switch. Release the air in the cuff and wrap it flatly around the middle of the upper arm, with the lower edge of the cuff 2 to 3 cm from the elbow socket, loosely enough to fit a finger. The chest piece of the stethoscope is placed at the most obvious point of the brachial artery pulsation. Close the valve and inflate until the brachial artery pulsation disappears and then raise it to a height of 20 to 30 cm. Deflate slowly (approximately 4 mmHg/sec), noting the change in brachial artery sound and mercury column scale. The scale indicated by the mercury column when the first pulsation sound is heard is the systolic pressure (the so-called high pressure). When the pulsation sound suddenly decreases or disappears, the scale indicated by the mercury column is the diastolic pressure (i.e. low pressure). When the measurement is completed, the remaining air in the gas band is exhausted, and the sphygmomanometer is tilted to the side at an angle of 45° in the direction of the mercury tank so that all the mercury in the mercury column is returned to the tank, and then the mercury tank switch is closed. The following points should also be noted when measuring blood pressure: (1) Blood pressure should be measured before resting for ten minutes to eliminate the effects of tension and exertion on blood pressure. (2) The healthy side of the limb should be selected for blood pressure measurement. (3) When blood pressure is found to be inaudible or abnormal, it should be remeasured. When remeasuring, the air in the cuff should be exhausted, and the mercury column should be lowered to the “0” point and measured again after a few moments. (4) After the first beating sound, if the mercury column is lowered to the lowest level and there is still sound, the diastolic pressure can be remeasured and the scale of the mercury column at the time of the sudden change of sound. (5) It is best to measure both limbs for the first time to help early detection of arterial entrapment and other diseases. (6) Patients who need to observe blood pressure for a long time should do four things: regular measurement, fixed location, fixed position, and fixed sphygmomanometer.