Higher blood pressure in the cold at night is caused by cold stimulating vasoconstriction and affecting the neuroendocrine system. Normal people can also experience elevated blood pressure in the cold at night, and the elevated blood pressure of hypertensive patients will be more obvious. Higher blood pressure at night is due to cold weather stimulation of peripheral vascular contraction of the human body, resulting in a relative increase in the amount of return blood caused by increased blood pressure, that is, vascular “heat expansion and cold contraction” phenomenon. At the same time, the low temperature of the external environment can make the body sympathetic nerve excitation secretion of catecholamines to ward off the cold, catecholamines can make the body heart rate increase, vascular contraction and lead to increased blood pressure. Cold blood pressure at night suggests that patients pay attention to keep warm, appropriate exercise, regular monitoring of blood pressure. Continuously elevated blood pressure suggests that patients consult a regular hospital in a timely manner, adjusting lifestyle habits and standardizing medication under the guidance of a professional physician.