Many people with hypertension find that their blood pressure tends to drop by summer, even to normal levels, thinking that it may be normal. The drop in blood pressure in summer is the result of thermal expansion and contraction of blood vessels, which leads to a decrease in sidewall pressure of blood against the vessel walls due to vasodilation and cannot change the situation that people with hypertension are still hypertensive. The diagnosis of hypertension requires that blood pressure be measured on different days, at different times, and several times, and that a systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg be found to be diagnosed. People who are clearly diagnosed with hypertension, if the blood pressure is often monitored in summer and found to fall, it means that the patient can standardize the monitoring of blood pressure, and the blood pressure should be measured before each dose of antihypertensive drugs, and if the blood pressure is normal or even low, the amount of antihypertensive drugs can be reduced or even discontinued that day. In the case of low blood pressure in summer, patients should not be too anxious, should continue to monitor blood pressure, if the blood pressure has decreased compared to the previous, still meet the criteria of taking antihypertensive drugs to lower blood pressure, should continue to take antihypertensive drugs.