Generally, it is recommended in clinical practice to measure blood pressure half an hour to one hour after taking antihypertensive drugs, because most antihypertensive drugs will take effect after half an hour to one hour, and some drugs are relatively slow to take effect, so they can also be measured after two hours. If the patient’s blood pressure has been relatively stable and he or she has been taking the drug for a period of time, the patient can have his or her blood pressure measured at any time to spot check whether the patient’s blood pressure is currently well controlled. If necessary, ambulatory blood pressure monitoring is recommended to assess the overall blood pressure over a 24-hour period. Especially for people whose blood pressure is still unstable while taking antihypertensive medications, ambulatory blood pressure monitoring can help to better modify the regimen of oral antihypertensive medications and guide treatment.