Blood pressure can be measured lying down, but before measuring blood pressure should pay attention to the following points: 1, the patient should be asked to rest quietly for more than 15-20 minutes. 2, to choose a quiet environment, the environment should not be too noisy. 3, the patient should be asked to avoid emotional tension, to eliminate nervousness, and the emotions should not be too agitated. 4, blood pressure measurement when the blood pressure measurement of the arm should be with the heart of the patient to keep at the same level, whether to choose the lying down position or choose a seat. Whether you choose to lie down or choose a seat, make the patient’s arm and the heart at the same level. 5, whether hypertensive patients or patients without high blood pressure, in the measurement of blood pressure when the two arms of the blood pressure is not the same, usually the advantage of the arm of the blood pressure to be higher than the other arm, higher than the arm of the 15-20mmHg, belongs to the normal physiological phenomenon.