All hypoglycemic drugs have certain side effects, such as the commonly used sulfonylurea hypoglycemic drugs, the main side effect is hypoglycemic reaction. The main side effect of glucagon is hypoglycemia and weight gain, but the risk of hypoglycemia is less than that of sulfonylureas. Gastrointestinal reactions are the main side effect of the commonly used biguanide hypoglycemic drugs such as metformin, with nausea, vomiting, and diarrhea. Acarbose hypoglycemic agents, which are mainly used to lower postprandial blood glucose, also have gastrointestinal reactions as a common adverse effect, such as bloating, increased gas, or diarrhea. Thiazolidinediones, the sensitizers of insulin, have a major adverse effect of weight gain and edema, which is more pronounced when combined with insulin, and thiazolidinediones have been associated with an increased risk of fractures and heart failure.