There are two kinds of electronic sphygmomanometers: arm type and wrist type. Wrist electronic sphygmomanometer is not suitable for people with peripheral circulation disorder. Because the measured values of wrist blood pressure and upper arm blood pressure of patients with peripheral circulation disorder will be very different. Patients with diabetes, hypertension, hyperlipidemia and the elderly will have different degrees of peripheral circulation disorders, so the wrist electronic sphygmomanometer is not suitable. Therefore, arm sphygmomanometer is generally used. Because the principle of electronic sphygmomanometer is different from that of mercury sphygmomanometer, it is not suitable for the following people: (1) obese people, (2) patients with arrhythmia, (3) patients with extremely weak pulse, severe dyspnea and hypothermia, (4) patients connected with artificial heart-lung machine, (5) patients with heart rate lower than 40 beats/min and higher than 240 beats/min, (6) At present, there are still "finger cuff sphygmomanometer" and "watch sphygmomanometer" on the market, which can only be called "finger pulse sphygmomanometer" strictly speaking. Because its measurement method determines that the measured "blood pressure" only means that there is a big gap between the last pulse pressure value and the real arterial blood pressure value, so it can not be used as a sphygmomanometer.