Why is blood pressure different when measured at home than when measured in the hospital? Which one is more accurate?

Many people told Huazi that the results of their blood pressure measurements at home and in the hospital were different. Why is this so? Which one should be taken as the standard? Huazi told him that measuring blood pressure seems simple, but in fact, there is a lot of knowledge involved. Where and when to measure will affect the measurement results.

1. Measuring blood pressure at home is more accurate. In most people's impression, medical examinations are most accurate in hospitals because hospitals have professional doctors and professional medical instruments and equipment. This perception is not a problem for most medical examinations, but it is not the case for blood pressure measurement. Blood pressure measured at home is more accurate than that measured in a hospital.

This is because the human body's blood pressure is easily affected by external factors and fluctuates. For most people, the hospital is an unfamiliar environment, which will increase their vigilance. Some people also have "white coat hypertension" and will be nervous when seeing a doctor, so the blood pressure measured in the hospital clinic is higher than the actual value. The home is a familiar environment for patients, it is easy to relax, and the measured blood pressure is closer to the actual value.

2. The standards for diagnosing hypertension at home and in hospitals are different. The blood pressure values ​​measured at home are lower than those in hospitals, so the diagnostic standard for hypertension is also lower than that in hospital clinics. In hospital clinics, the diagnostic standard for hypertension is blood pressure greater than or equal to 90/140 mmHg, while at home, blood pressure greater than or equal to 85/135 mmHg can be diagnosed as hypertension.

The key point of measuring blood pressure at home is to measure "resting blood pressure", which is the blood pressure of the human body in a quiet state after a full rest. For example, the blood pressure measured every morning after waking up, emptying urine, and before eating breakfast is the resting blood pressure. If it is after an activity, you need to sit quietly for 10 minutes to let the body completely relax before measuring blood pressure.

3. Things to note when measuring blood pressure at home 1. Choice of sphygmomanometer: When measuring blood pressure at home, it is recommended to choose an upper arm electronic sphygmomanometer, and it is not recommended to use a wrist or mercury sphygmomanometer. This is because the calibrated electronic sphygmomanometer is accurate and easy to use. However, the wrist sphygmomanometer has a large measurement error, and the mercury sphygmomanometer is inconvenient to use. If the mercury leaks out due to improper operation, it is easy to cause mercury poisoning.

2. Choice of measurement posture: It is best to sit when measuring blood pressure. At this time, the upper arm height is approximately at the same level as the heart, and the measured blood pressure is closer to the true value. For patients who can only rest in bed, a cushion can be added under the arm during measurement to make the arm at the same height as the heart.

3. Measure the left arm or the right arm: It is not that the left arm’s blood pressure is more accurate because the heart is on the left; nor is it that the right arm’s blood pressure should be measured because one is right-handed. Instead, both arms should be measured, and the side with the higher value should be used as the standard. When measuring for a long time, you can ignore the side with low blood pressure and only measure the arm with the higher value.

4. How many times a day: For people who take medication for a long time and have stable blood pressure control, it is sufficient to measure once every morning, or 2 to 3 times a week. However, for those whose blood pressure fluctuates greatly, those who have just started antihypertensive treatment, and those who are adjusting antihypertensive drugs, it is necessary to measure blood pressure in the early morning, morning, afternoon, and before bedtime, or do 24-hour dynamic blood pressure monitoring to determine the daily blood pressure fluctuations as a basis for the selection and adjustment of antihypertensive drugs.

5. What to do if the blood pressure values ​​are different at the same time: Each time you measure blood pressure, take 2 minutes to measure it twice. If the blood pressure values ​​at the same time differ by less than 5 mmHg, the lower value shall prevail. If the error is greater than 5 mmHg, measure it for the third time and the lower of the two similar blood pressure values ​​shall prevail.

In summary, when measuring blood pressure, the accuracy of self-testing at home is higher than that of measuring in a hospital clinic, but you should pay attention to the problems that are easy to encounter when measuring blood pressure. It is best to prepare a blood pressure record book to record the daily changes in blood pressure. When you go to the hospital for a follow-up visit, it can serve as an important basis for adjusting medication. I am pharmacist Huazi, welcome to follow me and share more health knowledge.