Tea does contain caffeine. Caffeine in tea can also be referred to as caffeine, and the amount of caffeine contained in tea is generally around 2% to 5%. Caffeine belongs to a kind of alkaloid compounds, part of the population in the intake of such substances can temporarily drive away the sleepiness, to play a certain effect of refreshing and waking up the brain. Tea contains more ingredients, including amino acids, minerals, tea pigments, tea polysaccharides, caffeine, alkaloids, etc. Appropriate consumption of tea can play a certain degree of fatigue, improve the degree of excitement and other effects. In daily life, appropriate drinking tea can play a certain health effect. But gastritis, gastric ulcer, gastroesophageal reflux people should not drink too much tea, especially strong tea.