Patients and friends often ask when is the best time to take antihypertensive medication and why most once-a-day antihypertensive medications are taken early in the morning? Here we will answer the question. Why antihypertensive drugs are taken in the early morning, we have to start from our morning peak hypertension, blood pressure is constantly changing within 24 hours, even for those with normal blood pressure, blood pressure will show a more obvious circadian rhythm, which is like our biological clock, with peaks and valleys. Physiologically, our blood pressure drops significantly during the first few hours of sleep, when we are going to sleep, our body enters a resting phase, our metabolic level decreases, we need less oxygen, our heartbeat slows down, and our blood pressure naturally drops. In the early morning, the heart rate increases and blood pressure rises during the process from sleep to awakening. The systolic and diastolic blood pressure of a normal person waking up usually increases by 10% to 20% compared to that during sleep. Studies have shown that most people with hypertension have a significantly higher rise in blood pressure in the early morning than normal people. The morning peak in blood pressure usually occurs between 6:00 a.m. and 10:00 a.m. Therefore, most of us with hypertension generally take our blood pressure medication in the early morning. Of course, there are patients with nocturnal hypertension that have to be treated differently. What damage can be done if blood pressure is too high early in the morning? Studies have shown that the relative risk of carotid atherosclerosis increases fivefold when blood pressure rises too much in the early morning; moreover, early morning hypertension is also very damaging to the kidneys; for every 10 mmHg increase in baseline systolic morning peak, the risk of stroke increases by 26%. To avoid high blood pressure in the early morning, we need to do more than just taking medication, we also need to monitor our blood pressure well. We need to get into the habit of taking blood pressure when we wake up early in the morning to observe the changes in morning peak blood pressure, and if we find that our blood pressure is too high, we need to consult a medical professional in hypertension for adjustment of antihypertensive medication and overall consultation.