The causes of high blood pressure at night include circadian neuromodulation disorder, failure to choose antihypertensive drugs correctly, psychological factors, and abnormal secretion of melatonin level. 1. Circadian neuronal imbalance: staying up late for a long time and working hard can cause circadian neuronal imbalance, resulting in higher blood pressure at night. 2. Failure to choose antihypertensive drugs correctly: taking short-acting antihypertensive drugs in the morning will lead to short action time of antihypertensive drugs, and the blood pressure is not effectively controlled, which will lead to the symptom of elevated blood pressure at night. 3. Psychological factors: emotional tension and anxiety at night can cause blood pressure to rise. 4. Abnormal secretion of melatonin level: Insufficient secretion of melatonin can cause elevated blood pressure at night. If you have symptoms of elevated blood pressure, you need to go to the hospital in time to have a relevant examination and make a reasonable medication plan.