Excitatory effect of nerve center: tea contains a lot of caffeine, and caffeine has the effect of excitatory nerve center, it can make the mind active, mental excitement, eliminate fatigue; However, excessive drinking of tea will cause insomnia, headache, tinnitus, palpitations, dizziness and other discomfort symptoms. Antispasmolysis and diuretic effect: theophylline in tea can relax muscles and smooth skin, so it can be used to treat bronchial asthma, biliary colic and other diseases. Moreover, caffeine in tea can inhibit the reabsorption of renal tubules, so it has good diuretic function.