2. The disadvantages of drinking Pu 'er tea. (1) Drinking fresh tea often can easily induce stomach trouble. Because of the short storage time, new tea contains more unoxidized polyphenols, aldehydes and alcohols, which has a strong stimulating effect on human gastrointestinal mucosa. Therefore, new tea should be drunk less, and new tea stored for less than half a month should be avoided, otherwise there will be many disadvantages. (2) Drinking tea on an empty stomach can dilute the gastric juice, reduce the digestive function, and increase the absorption rate of water, resulting in a large amount of bad ingredients in tea entering the blood, causing dizziness, palpitation, weakness of hands and feet and other symptoms. (3) Drinking tea with a fever is tantamount to "adding fuel to the fire", because tea contains theophylline, which has the effect of raising body temperature, and at the same time will greatly reduce or even disappear the cooling effect of drugs. (4) If you often have gastrointestinal ulcers, in fact, you should drink less tea, because caffeine in tea can promote gastric acid secretion, increase gastric acid concentration, induce ulcers and even perforation. (5) If you are often constipated, you should not drink tea. Because the polyphenols in tea have a certain astringent effect on gastrointestinal mucosa, constipation patients will aggravate constipation if they drink tea.