Drinking black tea will not significantly raise blood sugar in healthy people. Drinking black tea will raise blood sugar in patients with high blood sugar, but do not drink iced tea drinks sold on the market. Black tea is rich in carotene, vitamin A, calcium, phosphorus, magnesium, potassium, caffeine, leucine, lysine, aspartic acid and other nutrients, which can replenish the nutrients needed by the human body and maintain the normal physiological function of the body. Because of its sugar content is not high, the glycemic index is low, so patients with high blood sugar drink black tea although it will rise blood sugar but not much. Suffering from stones, neurasthenia, insomnia and other patients should not drink black tea. It is recommended to drink black tea to pay attention to the right amount, produce symptoms of discomfort in a timely manner to seek medical attention.