A blood glucose of 12.5mmol/L after 2h after breakfast is usually in the abnormal range. The normal range of 2h postprandial blood glucose is less than 7.8mmol/L, 2h after breakfast blood glucose 12.5mmol/L may be infections, stress and other causes of transient elevation of blood glucose, but also diabetes and other diseases, it is recommended to consult a doctor in a timely manner. If the 2h postprandial blood glucose is greater than or equal to 11.1mmol/L, and accompanied by three more and one less symptom (drinking, eating, urinating, weight loss), can be considered to diagnose diabetes mellitus, you can further improve the fasting blood glucose and glycated hemoglobin and other tests, after a clear diagnosis and actively lowering the sugar treatment, to avoid the occurrence of complications. It is recommended that patients with blood glucose of 12.5mmol/L after 2h after breakfast should go to the endocrinology department of regular hospitals in time to improve the relevant examinations and standardize the treatment under the guidance of the doctor, so as to avoid delaying the condition or causing adverse reactions.