Blood pressure is normal in the morning and suddenly rises in the afternoon due to physiologic, psychiatric, endocrine disorders, and irregular medication use. Hypertension can be diagnosed when the systolic blood pressure is ≥140mmHg and/or diastolic blood pressure is ≥90mmHg in three measurements taken on non-simultaneous days. If there is abnormal blood pressure usually should pay attention to monitor blood pressure. 1. Physiological: If you are nervous, agitated, excited or tired in the afternoon, there will be a transient increase in blood pressure, which will improve after rest. 2. Mental illness: Acute anxiety attacks will have a sense of loss of control, a sense of dying, causing serious autonomic disorders, there will be a sudden increase in blood pressure. 3. Endocrine diseases: pheochromocytoma, due to the indirect release of catecholamines will cause an increase in blood pressure, will bring about a sudden increase in blood pressure, accompanied by sweating, panic and other manifestations. 4. Irregular medication: If you don’t take medication as prescribed or take medication incorrectly, there will be one day of blood pressure fluctuation. If you have high blood pressure, you should consult the doctor in time and take standardized treatment.