Overall blood pressure may fluctuate with the seasons. Generally when the weather is cold, such as in winter blood pressure may increase; in summer when the weather is hot blood pressure tends to fall. This is because in hot weather, sweating increases, blood volume is lost, and the amount of circulating blood decreases; at the same time, high temperatures can cause blood vessels to dilate, so blood pressure tends to fall. However, in some cases, hot weather can cause the patient to be agitated and irritable, which can speed up the heart rate, thus causing the blood pressure to rise again. The temperature may cause fluctuations in the patient’s blood pressure, which is more damaging to target organs such as the heart, brain and kidneys. However, the fluctuation of blood pressure is affected by many factors, including emotions, sleep, diet and so on. So in hot weather, it is important to minimize the impact of various factors on blood pressure.