Hypertension is a highly prevalent disease, and there are 300 million people with hypertension in China. Nowadays, more and more families have purchased electronic blood pressure monitors, and blood pressure measurement can be performed at home. However, the majority of patients do not know much about the norms of blood pressure measurement, so the measured blood pressure value is not very accurate. To measure blood pressure at home, you need to pay attention to the following points: Before taking blood pressure, the subject should sit and rest quietly for at least 5 minutes, and no smoking or coffee should be consumed for 30 minutes. Talking or answering questions or talking on the phone may cause the blood pressure reading to be about 10 mmHg higher; be careful to remain quiet while taking the blood pressure. If the bladder is full (holding urine) it may cause the blood pressure reading to be about 10 to 15 mmHg higher; therefore, empty the bladder before taking the blood pressure. Maintain an upright sitting posture. If you are not sitting properly (slouching, lack of support for your back/lower extremities) – this can cause a high blood pressure reading of about 6 to 10 mmHg; when taking your blood pressure, you need to have your back against the back of a chair and your feet flat on the floor or footstool. When measuring blood pressure, the arm should be placed flat on the table so that the level of the measurement cuff is flush with the heart. Crossing your legs can make the blood pressure reading about 2 to 8 mmHg higher; do not cross your legs and have your feet supported when measuring blood pressure. It is also important to note that if the cuff is worn over clothing – it can skew the blood pressure reading by about 5 to 50 mmHg; therefore, it is best to have bare arms when measuring blood pressure. A cuff that is too small and too tight may result in a high blood pressure reading of about 2 to 10 mmHg; choose a cuff of the right size. Elderly hypertensive patients with an arm circumference of ≤26cm have a 5mmHg increase in blood pressure measured with a regular cuff compared to a large cuff, and elderly patients with an arm circumference of ≥27cm have a 4mmHg decrease in blood pressure measured with a large cuff compared to a regular cuff. people who are overly obese and have thick upper limbs should choose a cuff that is one size larger. It is also incorrect to measure only once. Measuring only once may cause errors in the machine and affect the interpretation of the blood pressure. Measurements should be repeated 1 to 2 minutes apart, and the average of the 2 readings should be taken and recorded. If the difference between the 2 readings of systolic or diastolic blood pressure is 5 mmHg or more, the measurement should be taken again and the average of the 3 readings recorded.