Diabetic patients need glucose-lowering drugs if their blood glucose is still not under control after diet and exercise control. The following talks about the types and characteristics of oral hypoglycemic drugs. The first major category: biguanide drugs The representative drug is metformin hydrochloride, which is recommended by the Chinese Medical Association as the first-line drug and the basic drug in the combination of type 2 diabetes. It can reduce HbA1c by 1-2% and can lead to weight loss. Metformin alone is not likely to cause hypoglycemia. Common side effects: Gastrointestinal reactions, such as nausea, vomiting, abdominal pain, etc. Contraindicated in patients with renal insufficiency, hepatic insufficiency, severe infection, hypoxia or undergoing major surgery. The second major category: sulfonylureas Sulfonylureas belong to insulin pro-secretory agents, which can reduce HbA1c by 1%-2% and are the main drugs recommended in diabetes guidelines for controlling hyperglycemia in patients with type 2 diabetes. Common side effects: prone to hypoglycemia and weight gain. Especially in elderly patients and those with hepatic and renal insufficiency. The third major group: thiazolidinediones Thiazolidinediones alone are not prone to hypoglycemia. However, they can increase the risk of hypoglycemia when used in combination with insulin or insulin-producing agents. Common side effects: fluid retention, induction or exacerbation of heart failure, hepatotoxicity, obesity, and increased risk of fracture (especially of the iliac and carpal bones). Contraindicated in patients with heart failure (New York Heart Failure Classification II or higher), active liver disease or transaminases elevated more than 2.5 times the upper limit of normal, and in patients with a history of severe osteoporosis and fractures, a history of bladder cancer, or the presence of unexplained sarcoid hematuria. Fourth major category: Glinides Non-sulfonylurea insulinotropic agents with unique advantages in lowering postprandial blood glucose and less prone to hypoglycemia. Common side effects: hypoglycemia and weight gain, but hypoglycemia occurs less frequently and to a lesser extent than sulfonylureas. Class 5: α-glucosidase inhibitors α-glucosidase inhibitors are suitable for patients with carbohydrates as the main food component and elevated postprandial blood glucose. α-glucosidase inhibitors do not increase body weight and have a tendency to cause weight loss, and hypoglycemia usually does not occur when this class of drugs is taken alone. Common side effects: Gastrointestinal reactions, bowel movements, bloating, nausea, vomiting, loss of appetite, and occasionally diarrhea, which usually resolve after two weeks. Starting with small doses and gradually increasing the dosage is an effective way to reduce adverse reactions. The sixth major category: dipeptidyl peptidase-4 inhibitors (DPP4 inhibitors) DPP4 inhibitors reduce the inactivation of GLP-1 in the body by inhibiting dipeptidyl peptidase 4 and increase the level of GLP-1 in the body.GLP-1 has the ability to increase insulin secretion and inhibit glucagon secretion in a glucose concentration-dependent manner. It has a dual hormonal regulation, so DPP4 inhibitors alone do not increase the risk of hypoglycemia, do not increase body weight, and rarely cause hypoglycemia. Caution: Do not use if you have pancreatitis or renal insufficiency. The seventh major class: SGLT2 inhibitors SGLT2 inhibitors are a new type of glucose-lowering drug that works mainly on the renal proximal tubular sodium-glucose transporters2 to prevent the reabsorption of filtered glucose in the kidney by inhibiting these transporters. Simply put, it reduces glucose reabsorption in the renal tubules and increases glucose elimination from the urine for the purpose of controlling hyperglycemia. Each drug has possible adverse reactions. It is recommended to choose the drug carefully and reasonably under the guidance of endocrinologists in regular hospitals and according to the specific condition and drug characteristics of each diabetic patient, and not to blindly believe in biased prescriptions or rumors and misinformation, so as not to delay the rescue and treatment.