High blood sugar can drink black coffee, but in moderation. Black coffee is a kind of drink without any modification, black coffee has no added milk and sugar, black coffee contains caffeine, and its calorie and fat content are low, so patients with high blood sugar can drink black coffee, but it is not recommended to drink too much, otherwise it will cause bloating and other gastrointestinal symptoms. It should be noted that patients with high blood sugar who suffer from stomach diseases try to drink less or no black coffee, because it will stimulate the gastric mucosa, which is not conducive to the recovery of the disease. Patients with high blood glucose should actively control their blood glucose level through dietary management, appropriate exercise, and medication if necessary, and the specific medication should be prescribed by the doctor.