Blood pressure is an important vital sign, and hypertension is a common chronic disease. In clinical practice, blood pressure measurement is one of the most frequent and important medical operations. Many families also purchase mercury column blood pressure monitors for health care or treatment purposes. However, many people do not really grasp the correct method of blood pressure measurement, and even some health care workers do not operate correctly when measuring blood pressure. When I take blood pressure in the clinic, I often encounter patients who point out with dissatisfaction, “Why don’t you tuck the stethoscope lower in the cuff?” When I tell patients that that is not correct, many of them don’t seem to believe me because the person who used to take his blood pressure always tucked the stethoscope piece down. Right. The following is the correct way to apply the mercury column blood pressure meter measurement. 1, measurement before a short rest is appropriate. Before measurement should sit still for 5 to 10 minutes, half an hour need to prohibit smoking, strong tea, coffee and wine; small cheap emptying. 2, the surrounding environment should be relatively quiet, to avoid excessive noise. The blood pressure measured in the hospital is often higher than that measured at home, in addition to the exhaustion of the journey, the hospital atmosphere and feel nervous and in awe of the doctor, the clinic environment is noisy and busy is also an important reason. 3, the cuff is the right length and width. Generally the length of the balloon in the cuff needs to encircle at least 2/3 of the circumference of the upper arm. obese people with ordinary size balloon cuff will cause the brachial artery can not be pressed, the measured blood pressure is high, attention should be paid to the central cuff capsule, placed on top of the brachial artery, the ideal cuff balloon length for the arm circumference of 80%, the width of the arm circumference of 40%. Children have long and thin arms, and the blood pressure values measured with standard cuffs are mostly low. 4.Appropriate body position and posture. It is recommended to take a sitting position with legs naturally hanging down and upper arms on the table, with the brachial artery flush with the heart position. The chair should have a backrest, no back support can lead to an increase in diastolic blood pressure of about 6 mm Hg. If the upper arm position is too high, the measured blood pressure value is mostly low, if the position is too low, the measured blood pressure value is mostly high. The first time the blood pressure is measured, both upper extremities should be measured for comparison, and the difference between the two sides should not exceed 20/10mmHg. Generally, the right side blood pressure is slightly higher than the left side, therefore, the office more measurement of the right upper limb blood pressure. 5, inflation should not be too violent, the deflation rate is moderate. Do not inflate the cuff too hard and too fast to avoid mercury overflow. Deflation speed of 2-3mmHg/sec is appropriate, too slow deflation of blood pressure values are more high, too fast measured blood pressure values are more low. During the descent of the mercury column, the first heartbeat sound heard from the stethoscope is the systolic blood pressure; when the heartbeat sound in the stethoscope disappears, the value is the diastolic blood pressure. If the mercury column reaches zero and the heartbeat still does not disappear, the value at the time of the change in sound is the diastolic pressure. In children, pregnancy, severe anemia, and aortic insufficiency, the diastolic sound often does not disappear on auscultation, and the value of diastolic pressure is taken as the value of the variable sound only. 6.Close the blood pressure gauge correctly. Squeeze out the gas from the cuff airbag, place the inflation balloon and cuff in the proper position, tilt the blood pressure meter 45° to the right, close the switch, and place the blood pressure meter properly.