Quality qualified electronic sphygmomanometer error ≤ 5 mmHg, blood pressure measurement in addition to the error of the sphygmomanometer itself, the actual and measurement methods have a great relationship, such as cuff tightness, external factors, in tension, excitement, stress, cold conditions can also appear blood pressure fluctuations. Most patients in the hospital because of nervousness measured blood pressure value than at home self-measured blood pressure 20-30mmHg, making blood pressure measurement value is not necessarily a true reflection of the patient’s blood pressure status, there are certain obstacles to the treatment of hypertension. At present many patients and even doctors on the electronic blood pressure monitor misunderstanding, that electronic blood pressure monitor than the traditional blood pressure monitor error, in fact, if not the arterial system within the invasive pressure measurement, are not considered to be the most reliable blood pressure. The basic principle of electronic sphygmomanometer and traditional sphygmomanometer is actually the same, are indirectly reflect the pressure changes in the vascular cavity through the pressure changes in the cuff, the advantage of electronic sphygmomanometer is easy to carry, easy to keep, simpler operation, repeatability, patients can be measured by one person, effectively avoid the white coat hypertension. Therefore, the latest guidelines also recommend patients to use upper-arm electronic blood pressure monitor, allowing patients to self-blood pressure management.