Drinking tea is an important factor to increase blood pressure. Research shows that the average systolic and diastolic blood pressure of tea drinkers is significantly higher than that of non-tea drinkers. After excluding other factors that affect blood pressure, such as age, weight and drinking, the survey shows that drinking tea still has obvious influence on blood pressure. It is speculated that this may be related to the fact that tea contains active substances such as caffeine, which accelerates the heart rate and increases the cardiac output, thus causing the blood pressure to rise. American scholars also found that normal people's blood pressure will rise in a short time after taking150mg of caffeine. We often meet in our daily life. Some people have dizziness and headache after drinking tea, probably because of blood pressure fluctuation.