The 2-hour postprandial blood glucose of 19.8mmol/L is elevated for both normal people and diabetic patients. 1. The normal value of 2-hour postprandial blood glucose for normal people is below 7.8mmol/L, so the 2-hour postprandial blood glucose of 19.8mmol/L is obviously elevated, which may be caused by eating too many sweets recently, or may be caused by diabetes, infections and other disease factors, and it is recommended to consult with a medical professional for a clear diagnosis. 2. For patients who have been diagnosed with diabetes in the past, the general 2-hour postprandial blood glucose needs to be controlled at 10mmol/L or less, so the 2-hour postprandial blood glucose of 19.8mmol/L does not reach the control target, which may cause diabetic complications, such as diabetic ketoacidosis, diabetic hyperosmolar hyperglycemia syndrome, etc. When the patient has a 2-hour postprandial blood glucose, it is obvious that it is elevated. When a patient has a 2-hour postprandial blood glucose of 19.8 mmol/L, it is recommended that he or she be seen by a physician.