A blood sugar of 16 mmol/L does not indicate several types of diabetes. There are four types of diabetes, type 1 diabetes, type 2 diabetes, special type of diabetes and gestational diabetes. Elevated blood glucose is common to all types of diabetes and the type of diabetes cannot be diagnosed on the basis of blood glucose values. Diabetes typing requires a combination of age, medical history, pancreatic function, autoimmune antibodies, and genetic background. 1. Type 1 diabetes: Type 1 diabetes is usually found in adolescents and young adults, with absolute lack of pancreatic islet function, rapid onset of diabetes, diabetic ketoacidosis, need for insulin at an early stage, and diabetes-related autoimmune antibodies. 2. Type 2 diabetes mellitus: type 2 diabetes mellitus occurs in middle-aged and old-aged people, but now the age of onset of diabetes mellitus is gradually decreasing, combined with obesity, insidious onset of pancreatic islet function, early manifestation of insulin resistance. 3. Special type of diabetes: special type of diabetes is induced by special causes of diabetes, such as chronic pancreatitis, Cushing’s syndrome, acromegaly and so on. 4. Gestational diabetes: Gestational diabetes refers to the first diagnosis of diabetes during pregnancy, which usually returns to normal after delivery. Blood sugar 16mmol / L should be timely to the hospital, under the guidance of the doctor treatment, to avoid delay.