Methods for measuring blood pressure

As our quality of life improves, we consume too much food, and excessive calories lead to high blood pressure. High blood pressure is a killer of our health, so we must do a good job of preventing high blood pressure. High blood pressure is related to diet, as well as obesity and age. Therefore, many middle-aged and elderly people must do a good job of preventing high blood pressure once they become obese.

We can also measure our blood pressure at home as long as we have the instrument. However, many people do not measure their blood pressure the same way every time and often have problems. In fact, there must be a very correct method to measure blood pressure.

1. The person being measured should rest quietly for at least 5 minutes. Smoking and drinking coffee are prohibited within 30 minutes before measurement, and the bladder should be empty.

2. The person being measured should sit down, preferably in a chair with a backrest; expose the right upper arm and place the elbow at the same level as the heart. If peripheral vascular disease is suspected, blood pressure should be measured in both arms during the first visit. In special circumstances, blood pressure can be measured in a supine or standing position; the elderly, diabetics and those who often suffer from orthostatic hypotension should measure blood pressure in a standing position. Standing blood pressure measurement should be performed 2 minutes after changing from supine to standing position. Regardless of the subject's position, the sphygmomanometer should be placed at heart level.

3. Use a cuff of appropriate size. The air bag inside the cuff should cover at least 80% of the upper arm. Most people's arm circumference is 25 to 35 cm, so it is appropriate to use an air bag cuff with a width of 13 to 15 cm and a length of 30 to 35 cm. Obese people or those with large arm circumference should use a large cuff, and children should use a smaller cuff.

4. Tie the cuff tightly around the subject’s upper arm, with the lower edge of the cuff 2.5 cm above the elbow. Place the probe of the stethoscope over the brachial artery in the antecubital fossa.

5. It is best to choose a mercury column sphygmomanometer that meets measurement standards for measurement. If a mechanical sphygmomanometer or an electronic sphygmomanometer that meets international standards (BHS and AAMI) is used, it is necessary to measure and calibrate the value simultaneously with the mercury column sphygmomanometer.

6. During measurement, inflate the balloon quickly. The pressure inside the balloon should reach the point where the radial artery pulsation disappears and then rise by 30 mmHg (4.0 kPa). Then, deflate slowly at a constant rate (2 to 6 mmHg/sec). The deflation rate is slower when the heart rate is slower. After taking the diastolic reading, quickly deflate to zero.

7. During the deflation process, listen carefully to the Korotkoff sounds and observe the vertical height of the convex surface of the mercury column during the first and fifth phases of the Korotkoff sounds. The systolic pressure reading is taken when Korotkoff sounds are in phase I, and the diastolic pressure reading is taken when Korotkoff sounds are in phase V (when the sound disappears). For children, pregnant women, patients with severe anemia, aortic valve insufficiency or those with persistent Korotkoff sounds, the diastolic pressure is determined as the IV phase (change in sound) of the Korotkoff sounds.

8. The unit of blood pressure is millimeters of mercury (mmHg). The conversion relationship between millimeters of mercury and kilopascals (kPa) is 1mmHg=0.133kPa.

9. The measurement should be repeated every 2 minutes and the average of the two readings should be recorded. If the difference between the 2 measured systolic or diastolic blood pressure readings was >5 mmHg, the measurement was repeated 2 minutes later and the average of the 3 readings was taken.

In the above article, we introduced that as our quality of life improves, the excessive calorie intake of food leads to high blood pressure. Middle-aged and elderly friends need to do a good job in preventing high blood pressure. They can measure their blood pressure themselves, but they must use the correct method. The method of measuring blood pressure is introduced in detail in the above article.