Common infections in diabetic patients include urinary tract infections, respiratory tract infections, and digestive system infections. Diabetes mellitus is prone to various infections, with bacterial infections being the most common, and fungal and viral infections also occurring in diabetic patients with poor glycemic control. Diabetic infections can form a vicious circle, i.e., infections lead to uncontrollable hyperglycemia, and hyperglycemia further aggravates infections. The probability of surgical site infection is high in diabetic patients. Infection can induce acute complications of diabetes and is one of the important causes of death in diabetes. When diabetic patients have co-infections, it is recommended that they seek medical attention promptly to avoid delays.