Correct measurement of blood pressure

There are about 270 million people with hypertension in my country, and one in every four people suffers from hypertension. More and more people choose to measure their blood pressure at home. There are some issues that need to be paid attention to during blood pressure measurement. Let's learn about them.

1. When is the best time to measure blood pressure?

The human body's blood pressure fluctuates with two peaks and one valley under the influence of the biological clock. The peaks are at 6-10 am and 16-20 pm respectively. The peak blood pressure in the morning is higher than that in the afternoon, and the blood pressure reaches the lowest valley in the early morning. It is best to measure blood pressure during the peak period to understand the highest blood pressure value of the day, usually in the morning after getting up. Blood pressure should be measured before going to bed or after meals at night. Measure blood pressure in time when you feel uncomfortable.

2. Choose the left arm or the right arm?

Generally, blood pressure is measured in the right upper arm, because the right brachial artery comes from the branch of the brachiocephalic trunk, while the left brachial artery comes from the left subclavian artery. The brachiocephalic trunk is a larger branch of the aorta, and the left subclavian artery is a smaller branch. The blood pressure measured in the right arm will be higher than that in the left arm and more accurate. The European Society of Cardiology recommends measuring the blood pressure of both upper limbs for the first time. When the blood pressure values ​​on both sides are different, the higher side should be selected as the fixed arm for future measurements. It is recommended to measure both sides from time to time. If the difference is between 5 and 10 mmHg, don't worry too much. Ensuring the stability of the measurement is more accurate than choosing an arm, but if the difference is greater than 20 mmHg, it may be vascular stenosis or blockage, and you should go to the hospital as soon as possible.

3. What posture should be used to measure blood pressure?

As long as the upper arm is level with the heart, the measurement can be made while sitting, lying or even standing.

4. Should I take antihypertensive drugs first or measure my blood pressure first?

Blood pressure will be affected by the medication after taking it, so it should be measured before taking the medication. If you want to monitor the therapeutic effect after taking the medication, measure blood pressure while taking the medication normally.

5. Is the electronic sphygmomanometer not as accurate as the mercury sphygmomanometer?

Mercury sphygmomanometers are accurate, but they require high technical skills from the person measuring them, and it is difficult to measure with an accuracy of 1 mmHg. Electronic sphygmomanometers are equally accurate, easy to operate, and have clear displays. They can also automatically record previously measured blood pressure values. Upper arm electronic sphygmomanometers are more suitable for home blood pressure monitoring. Regardless of the type of sphygmomanometer, it should be calibrated regularly to avoid inaccurate measurement results.

6. How to grasp the measured values?

Normal: systolic pressure <120mmHg, diastolic pressure <80mmHg; high: systolic pressure 120~139mmHg, diastolic pressure 80~89mmHg; high blood pressure: systolic pressure ≥140mmHg, diastolic pressure ≥90mmHg measured three times on different days. The blood pressure value cannot be rounded off, otherwise it will not reflect the actual blood pressure situation.

To measure blood pressure correctly, you must pay attention to the following:

1. Don’t hold your urine. A full bladder may cause high blood pressure.

2. Don't smoke. Smoking can cause vascular spasm and affect blood pressure values. Don't smoke half an hour before measuring blood pressure. Of course, don't drink alcohol, tea or coffee.

3. Don't take off your clothes. Studies have shown that taking off clothes can cause a temporary increase in blood pressure, especially taking off a pullover. It is recommended to rest for 6 minutes after taking off clothes before measuring blood pressure. As long as the thickness of the clothes does not exceed 0.5 cm, you can measure through the clothes without affecting the measurement results. Some people are used to rolling up their sleeves, but if the clothes are too thick, they will wrap the upper arms tightly and make the blood pressure lower than it actually is.

4. Don't cross your legs. If you cross your legs when measuring your blood pressure, the measurement result will be higher than the actual value. Your legs should be kept flat and natural, without crossing them.

5. Do not make the cuff too loose or too tight. It is best to allow 1-2 fingers to fit between the cuff and the arm. If the cuff is too tight, the blood vessels will be compressed before air is injected, and the measured blood pressure value will be too low. If the cuff is too loose, the measured value will be too high.

6. Avoid dehydration. Excessive exercise, excessive sweating, and insufficient drinking of water can cause the body to be dehydrated or even dehydrated. Dehydration can lower blood pressure.

7. Don’t talk. Even a casual chat while measuring your blood pressure may increase your blood pressure. It is best to sit quietly for 5-10 minutes before measuring your blood pressure.