Medicines used to treat diabetes are insulin and oral hypoglycemic drugs. 1. Insulin is categorized into rapid-acting, short-acting, intermediate-acting and long-acting insulin according to its duration of action. Short-acting and rapid-acting insulin is mainly used for controlling postprandial blood glucose, medium- and long-acting insulin is mainly used for controlling nocturnal and fasting blood glucose, and there is also premixed insulin, which can take into account the functions of both. 2. Oral hypoglycemic drugs are categorized into various types according to different mechanisms of action: (1) Drugs that promote insulin secretion as their main action: sulfonylureas and glinides directly stimulate pancreatic β-cells to secrete insulin, representing the drugs glimepiride, nateglinide, etc.; dibrachialyl peptidase 4 inhibitors promote pancreatic β-cell secretion of insulin by reducing the breakdown of enteric proinsulin in vivo, representing the drug selegiline and so on. (2) Drugs that lower blood glucose through other mechanisms: the main effect of biguanides is to reduce the output of hepatic glucose, on behalf of the drug metformin; the main effect of thiazolidinediones is to improve insulin resistance, on behalf of the drug pioglitazone, etc.; the main effect of α-glucosidase inhibitors is to slow down the digestion and absorption of carbohydrates in the intestinal tract, on behalf of the drug acarbose, etc.. There is a wide range of medications for diabetes, and individualized medication regimens should be developed by a medical professional based on the condition of the patient.