The causes of elevated blood pressure in winter include physiological factors, such as overwork, weather changes, and pathological factors such as having primary hypertension. 1. Physiological factors: In winter, the temperature is low, the blood vessels on the surface of the skin contract, and the change of temperature easily causes the contraction of blood vessels, which leads to the increase of blood pressure. If the blood pressure is only temporarily elevated, you should pay attention to rest and keep warm. 2. Pathological factors: Hypertension is diagnosed by three measurements of blood pressure not taken on the same day, with systolic blood pressure ≥140mmHg and/or diastolic blood pressure ≥90mmHg. In addition to primary hypertension, endocrine diseases and renal diseases may also cause changes in blood pressure. You should seek prompt medical attention if you suffer from hypertension.