Drinking green tea usually cause insomnia.Green tea contains a certain amount of caffeine, and the intake of caffeine is easy to affect sleep. Green tea is made of fresh leaves or buds of tea leaves, and then made of green and drying without fermentation.Green tea contains tea polyphenols, green leaves, and caffeine. Caffeine contained in green tea will release excitement neurotransmitters, which makes the neuron extremely sensitive lead to excessive brain activity. It is difficult to fall asleep and cause insomnia.Therefore, it is not recommended to drink green tea at night to avoid affecting sleep. If you have anemia and gastric ulcer, it is recommended not to drink it, so as not to drink adverse reactions.If drinking green tea affects sleep, it is recommended to seek medical treatment in time, and treat it according to the doctor’s advice.It is recommended to drink green tea in moderation to avoid long -term excessive drinking, so as not to cause adverse effects on the body.