Metformin belongs to oral hypoglycemic drugs. Its hypoglycemic side effects can be categorized into common, rare and uncommon and so on, as follows: 1. Common: such as taste disorder, gastrointestinal abnormalities, such as nausea, vomiting, diarrhea, abdominal pain, loss of appetite and so on. 2. Rare: such as stool abnormalities, myalgia, dizziness, nail abnormalities, chest discomfort, hypoglycemia, hot flashes, palpitations, and so on. 3. Rare: such as lactic acidosis, erythema, itching, urticaria, and so on. It should be noted that people who are allergic to this drug, severe hepatic or renal insufficiency, dehydration, severe infection, trauma, etc. should not use this drug for treatment. When patients experience these side effects while taking Metformin, they should stop taking the drug and actively seek medical attention to consider whether to change to another drug under the guidance of a doctor.