A female hypertensive patient, 48 years old, had recurrent head distension for 4 years. Normally, ambulatory blood pressure is close to the level of home self-measured blood pressure, but this ambulatory blood pressure is significantly higher than home self-measured blood pressure or even office blood pressure. This is a rare occurrence and may be due to excessive stress or anxiety while wearing ambulatory blood pressure. For hypertensive patients with anxiety, the white coat effect is more pronounced, and either office BP or ambulatory BP monitoring may overestimate the true daily BP level, and more emphasis should be placed on continuous recording of home self-measured BP. She brought the wrist blood pressure monitor she uses daily to the clinic, and after measuring and comparing it to the one used in the hospital, she found that it was not very different from the one used in the hospital and could be used as a reference for daily use. Because she felt that the wrist blood pressure monitor was not convenient enough, she further asked: Should I buy a watch-type blood pressure monitor? 1, the main way of blood pressure measurement and the type of blood pressure monitor Currently there are three commonly used blood pressure measurement methods, which are office blood pressure measurement, home self-measurement blood pressure and ambulatory blood pressure monitoring. The office blood pressure is the traditional blood pressure measurement method, the past clinical research about the relationship between hypertension and cardiovascular disease are based on this blood pressure measurement method, this method is also accepted by the daily treatment, or the current diagnosis of “hypertension” preferred method. Home self-measured blood pressure eliminates the white coat effect and stress and anxiety to the greatest extent possible, and is theoretically more reflective of the true blood pressure level in daily life. Ambulatory blood pressure also eliminates the white coat effect and has the unique advantage of being able to monitor blood pressure levels at night. Therefore, all three of these blood pressure measurement methods have their own unique clinical significance and can complement each other when it comes to a comprehensive understanding of the condition. The following 3 types of blood pressure monitors are also commonly used: mercury column sphygmomanometer, pneumatic sphygmomanometer and electronic sphygmomanometer, respectively. Because electronic sphygmomanometers are easy to carry and measure, and because certified electronic sphygmomanometers are accurate in measurement, they are now increasingly recommended as a tool for measuring blood pressure. In most cases, the misconception that electronic blood pressure monitors are not accurate enough is due to the fluctuating nature of blood pressure itself. Mercury column sphygmomanometers require simultaneous auscultation, and the measurement data is more intuitive and stable. Although there is a tendency for electronic sphygmomanometers to be gradually phased out, they are still one of the important medical instruments, at least for the time being. Pneumatic blood pressure has similar portability to electronic sphygmomanometers, which require auscultation, but do not require batteries, and have certain advantages when used in areas with limited transportation or material shortage. 2, watch-type blood pressure monitor working principle and accuracy With the development of wearable health monitoring devices, watch-type blood pressure monitors are increasingly appearing in the market. A watch-type sphygmomanometer is a watch that is comparable in size to an ordinary watch and can be worn continuously for a long period of time like a watch, but can also monitor human blood pressure at any time. The watch type blood pressure monitor can be divided into two types from the principle of oscillometric method and photoelectric method. The oscillometric method has a pressurized air bag, which needs to be inflated and pressurized when measuring blood pressure, similar to the wrist blood pressure monitor, so this blood pressure monitor is equivalent to a pocket-sized version of the wrist blood pressure monitor. The “blood pressure watch” that measures blood pressure by the photoelectric method does not obtain the blood pressure value by directly blocking the arterial blood flow and measuring the pressure, but by sensing the photoelectric and electrocardiographic information, and then converting it to obtain the blood pressure data. Since it is a conversion, it involves a conversion factor, which must be corrected by a large amount of actual measurement data. A fixed conversion factor has been set when the watch is manufactured, but when it is applied to each person, it still needs to pay attention to the accuracy of different blood pressure and pulse rate. From the working principle, the oscillometric measurement should be more reliable. However, because the oscillometric method requires pressure and inflation, it can cause mild discomfort to the body. The photoelectric method can achieve non-sensory monitoring, which really meets the requirements of wearable monitoring devices. In view of the limitations of the photoelectric method of measurement, it is recommended that after purchasing this watch sphygmomanometer, it must be compared with the upper arm type electronic sphygmomanometer or mercury column sphygmomanometer. 3.Should I buy a watch-type blood pressure monitor? Blood pressure monitoring devices are important data about the vital signs of the human body, and inaccurate measurement may bring harm to the body. Therefore, any type of blood pressure monitor is a medical device, the state has mandatory measures to regulate. Only blood pressure monitors registered by the Chinese State Food and Drug Administration (CFDA), or those that comply with the “YY0670-2008 Non-invasive Automatic Blood Pressure Measurement” standard, can be legally marketed and sold in China. Otherwise, regardless of whether the manufacturer claims its product is a medical device, it is not legal and is difficult to buy in brick-and-mortar stores. For the blood pressure measured by the wrist blood pressure monitor or finger blood pressure monitor, although both have a certain reference value, but because the measurement site is further away from the heart, the vascular variability is large, and the measured value is more volatile. Therefore, the blood pressure measured by these blood pressure monitors can be used as a daily reference, but cannot be used as a basis for adjusting treatment plans. As a wearable device that is more easily accepted by the public, a watch-type blood pressure monitor can collect important parameters such as human blood pressure and heart rate. I personally recommend trying to choose an officially certified device and reading the instructions carefully before using it to best collect your own blood pressure level more accurately. When the blood pressure fluctuates greatly or needs to adjust the treatment plan, you must need to go to the hospital in time.