High blood pressure at night may be related to bad habits, irrational medication, disease factors such as sleep apnea syndrome, circadian neuromodulation and other reasons. 1. Bad life habits: there are some triggers that induce the rise of blood pressure, such as too much smoking, drinking alcohol before going to bed, drinking strong tea, coffee and staying up late, etc., which may also cause high blood pressure at night. 2. Unreasonable medication: If the correct antihypertensive medication is not selected, it will result in the short duration of maintenance of the efficacy of the antihypertensive medication. As a result, it cannot cover the night time period, which will lead to the rise of blood pressure at night. 3. Disease factors. If respiratory sleep apnea occurs during nighttime sleep, it can also lead to nocturnal hypertension. If circadian neuromodulation is dysregulated, it can cause an increase in sympathetic excitability at night. Sympathetic excitation can act on neurotransmitters, which act on the adrenal glands to release a variety of catecholamines, including epinephrine, norepinephrine, and dopamine, which are vasoactive substances that can cause vasoconstriction and elevated blood pressure. High blood pressure at night requires prompt medical attention and systematic treatment under the guidance of a doctor to control the blood pressure steadily.