The usual site for blood pressure measurement is 2.5 cm above the elbow fossa on the upper arm, both left and right sides, and blood pressure is usually measured using the cuff pressurization method. Blood pressure is measured by wrapping the cuff of the sphygmomanometer evenly against the skin around the upper arm so that the lower edge is about 2.5 cm above the elbow fossa and the center of the cuff is located on the surface of the brachial artery, and when the brachial artery pulsation is touched, the stethoscope component is placed on the pulsation to begin measuring blood pressure, and when the blood pressure on the left and right side of the upper arm is inconsistent, the side with the higher blood pressure prevails. Blood pressure measurement also needs to pay attention to several points: First, blood pressure measurement value is affected by a variety of factors, so the person being examined for half an hour to abstain from salt and coffee, empty the bladder, quiet state, at least 5 minutes rest in a chair with a backrest; Second, generally take a sitting position, in special cases can take the supine position or standing position; Third, the normal bilateral upper extremity blood pressure difference in 5-10mmHg, if beyond this range is abnormal. See multiple aortitis or congenital arteriovenous malformation; Fourth, the correct measurement of blood pressure at least three times, non-same day blood pressure value reaches or exceeds 140mmHg systolic or 90mmHg diastolic, can be diagnosed hypertensive disease.