The incidence of diabetes is getting younger and younger, and many young people in their 20s are seen to have diabetes in clinical practice. There are two common types of diabetes in young people: first, type 1 diabetes, in which the patient has no family history of diabetes, has a high blood glucose level with ketosis at the time of consultation, and has a significant weight loss and a thin body type. If the patient is absolutely deficient in insulin secretion, the patient should be treated with insulin for life. The clinical characteristics of type 2 diabetes are different from those of type 1, often with a family history of diabetes, a relatively obese body type, moderately high blood glucose levels, generally not combined with ketosis, islet function tests suggest a relative lack of insulin, patients can take oral hypoglycemic drugs for treatment.