The normal blood pressure of human body is below 140/90mmHg, but any systolic blood pressure greater than or equal to 140mmHg, and/or diastolic blood pressure greater than or equal to 90mmHg is high blood pressure. However, it is necessary to pay attention to the following misunderstandings: 1. Occasional measurement of blood pressure once found that the blood pressure is abnormal does not represent a problem, it must be non-same day at different times of the day are higher than the normal value of the blood pressure can be diagnosed with hypertension. 2. 10-15 minutes of rest before each measurement is recommended to avoid the exercise of the blood pressure is higher after the measurement of blood pressure is not representative of the blood pressure. 3. Bilateral arm should be measured, the measurement of the standardized to keep the heart and the blood pressure band in the same horizontal position, and the head of the stethoscope should not be inserted in the cuff of the sphygmomanometer.