High blood pressure in the morning and normal at noon may be hypertension, or it may be caused by normal rhythmic fluctuations in blood pressure. 1. Normal people’s blood pressure shows a clear circadian rhythm, manifesting itself as a double peak and a valley, with a peak at 6-10 a.m. and 4-8 p.m., and a significant decrease in blood pressure at night. Therefore, if the blood pressure is high in the morning and normal at noon, it is not necessarily high blood pressure. 2. The diagnosis of hypertension generally requires three measurements of systolic blood pressure ≥ 140mmHg and/or diastolic blood pressure ≥ 90mmHg on non-same day. Therefore, hypertension can be diagnosed when the blood pressure is higher than normal in the morning but normal at noon. If your blood pressure is higher than the normal range several times, you should consult a doctor for diagnosis.