In summer, when the temperature is higher, the body’s peripheral blood vessels are in a diastolic state, and the pressure on the peripheral blood vessels is lower, so the blood pressure is lower than in winter, or even in the normal range. In winter, as the temperature drops, the body’s peripheral blood vessels are in a state of contraction, and the pressure on the peripheral blood vessels is also greater, so blood pressure is often higher in winter than in summer, similar to the principle of heat expansion and cold contraction in physical phenomena, so patients are advised to pay attention to the status of home self-measurement of blood pressure. Home self-measured blood pressure is defined as a blood pressure level higher than 140/90 mmHg for more than three times on non-same day. Patients are advised to visit the outpatient cardiology department of their local hospital and listen to the advice of a cardiology specialist on whether to initiate medication for hypertension and regular outpatient follow-up is required. In the case of low blood pressure in summer or high blood pressure in winter, a comprehensive assessment of the need to withdraw appropriate medication or increase appropriate medication to reduce the fluctuation of the patient’s blood pressure level will be made.