Drinking tea after the stomach upset, may have to do with stomach diseases, drinking tea on an empty stomach as well as strong tea and so on. 1. Strong tea: strong tea because of caffeine and theophylline and other stimulating substances are relatively high, easy to cause gastrointestinal mucosa by adverse stimulation, and then cause gastrointestinal discomfort. 2. Drinking tea on an empty stomach: it is easy to cause the caffeine and theophylline in the tea to stimulate the gastrointestinal mucosa directly, causing gastrointestinal discomfort. 3. Stomach diseases: such as gastric ulcer and chronic gastritis, the irritating substances in tea will also cause gastric mucosal stimulation, but also cause excessive secretion of gastric acid, causing gastric discomfort. Check the patient needs to exclude non-disease factors induced gastric discomfort, and then need to go to the regular hospital as soon as possible to receive further examination and treatment.