Is the measurement data of electronic blood pressure monitor accurate？

The Chinese Guidelines for the Prevention and Treatment of Hypertension (2024 Edition) have been officially issued. One of the biggest changes in the new guidelines is the strong recommendation for electronic blood pressure monitors, which explicitly states that "mercury blood pressure monitor are not recommended" and instead recommends the use of upper arm electronic blood pressure monitors that have been validated for accuracy. This marks that electronic blood pressure monitors have become the main tool for blood pressure measurement in China. In 2013, China signed the Minamata Convention, which required China to gradually cease the production of mercury blood pressure monitor. As a result, mercury blood pressure monitor will be gradually phased out.

You may have noticed that more and more medical institutions are now using electronic blood pressure monitors. Many people think that electronic blood pressure monitors are inaccurate, but this view is incorrect. As long as the purchased electronic blood pressure monitor has been verified by international standards (please carefully read the instruction manual when purchasing), its accuracy can be trusted.

It should be noted that currently, arm electronic blood pressure monitors are more accurate than wrist blood pressure monitors for measuring blood pressure, and the accuracy of wrist blood pressure monitors still needs to be evaluated,Someone said that the blood pressure I measured at home is different from the value I measured in the hospital. Does this mean that my blood pressure monitor is inaccurate?

• No, as long as the method of measuring blood pressure is correct, your own blood pressure measurement can better reflect your true blood pressure than the value measured by a doctor. Measuring blood pressure in the hospital can cause the "white coat phenomenon", resulting in blood pressure being higher than the actual blood pressure. Measuring blood pressure at home will not result in this situation, making it more reliable.
• Another possibility is that blood pressure is constantly changing. Our blood pressure is constantly fluctuating, with a daily difference of 30-40mmHg, ranging from 140/90 in the morning to 120/80 in the afternoon. So measuring blood pressure at home and at the hospital may be completely different.
• Actually, even if you use the same blood pressure monitor and measure it every few minutes, the value you get each time will be different. Do you believe it? This is not because the blood pressure monitor is inaccurate, but because our blood pressure is constantly changing and not a fixed value. The occurrence of this phenomenon does not mean that the electronic blood pressure monitor is inaccurate, on the contrary, it precisely indicates that the electronic blood pressure monitor is very sensitive.

Our human body has a complete and delicate regulatory system for blood pressure, which can adjust the blood pressure level in a timely and precise manner according to changes in the internal and external environment and physiological needs: it will be lower when we close our eyes to rest, and higher when we speak; When speaking calmly, it will be lower, and when making loud noises, it will be higher; Leaning back on the chair will result in a lower measurement, while standing up straight will result in a higher measurement; When the legs are flat, they will be lower, and when the legs are crossed, they will be higher; When the environment is quiet, it is lower, and when the surroundings are noisy, it will be higher. Even if you don't notice any changes yourself, measuring blood pressure several times in a row will still be different, indicating that the pressure of blood flow in the arteries has been fluctuating within a certain range.

That's why we have many requirements when measuring blood pressure, such as: keeping the surrounding environment as quiet as possible when measuring blood pressure; Before measuring blood pressure, subjects should sit quietly for at least 5 minutes, refrain from smoking or drinking coffee for 30 minutes, and empty their bladder; When measuring blood pressure, it is advisable to sit in a seated position, preferably in a backrest chair; At the first visit, the blood pressure of the left and right upper arms should be measured, and later the blood pressure of the upper arm on the side with the higher reading should be measured; Measurements should be repeated 1-2 minutes apart, and the average of the two readings should be recorded; If there is a difference of more than 5mmHg between the two readings of systolic or diastolic blood pressure, they should be measured again and the average of the three readings should be recorded

These requirements for blood pressure measurement not only indicate that there are many factors that affect blood pressure, but also reflect that blood pressure fluctuates constantly, so the blood pressure values measured each time will be different. Do not assume that electronic blood pressure monitors are inaccurate just because of this phenomenon.

Compared with mercury blood pressure monitor, electronic blood pressure monitor have lower requirements for measurement technology, are easy to use, and can avoid human errors. However, patients with atrial fibrillation or frequent premature beats may have significant measurement errors when using electronic blood pressure monitors. In this case, it is best to take multiple measurements, take the average, or use a mercury column sphygmomanometer for measurement.

Reminder: When using an electronic blood pressure monitor to measure blood pressure at home, if the average blood pressure is ≥ 135/85 mmHg, it can be diagnosed as hypertension, provided that your blood pressure monitor meets the standards and the blood pressure measurement method is standardized.

Overall, electronic blood pressure monitors are reliable and particularly suitable for measuring blood pressure at home. Some people say that electronic blood pressure monitors are inaccurate, but this is a misconception.