For patients who are to be tested for hypertension IV, they should be on a sodium-prescribed diet for at least three days and off all antihypertensive medications for at least three weeks, diuretics for at least four weeks, and birth control pills for at least six weeks prior to the blood test. Before blood collection, it is recommended that the patient remain in the prone position for at least 1.5-2 hours before blood collection, and after measuring the hypertension in the inspired state, the blood should be taken in the upright position after the basal state, that is, after two hours of activity.