Usually, diabetic patients stop taking medication for three months may cause elevated blood glucose, ketoacidosis, hyperosmolar coma and so on. 1. Elevated blood glucose: the pancreatic islet function of diabetic patients is abnormal, and the use of drugs is to maintain normal insulin secretion in the patient’s body, so that blood glucose control in the normal range. Therefore, stopping the drug for three months will cause blood sugar increase. 2. Ketoacidosis: diabetic patients stop taking medication for three months can lead to abnormal glucose metabolism in the patient’s body, high blood glucose, impaired glucose utilization, increased fat oxidation, increased ketone body production, which can cause ketoacidosis. 3. Hyperosmolar coma: poor glycemic control will cause a significant increase in plasma osmolality, prone to hyperosmolar coma, consciousness barrier, etc., the need for timely diagnosis and treatment. Diabetic patients should not stop taking medication without authorization, if the above symptoms occur three months after stopping medication, it is recommended to go to a professional hospital to clarify the cause of the disease under the guidance of the doctor to carry out further examination and treatment.