Postprandial blood glucose is the value of blood glucose measured 2 hours after a meal. For both ordinary people and diabetic patients, postprandial blood glucose of 15.0mmol/L is high, and it is necessary to go to the endocrinology department to perform blood glucose measurement, glucose tolerance test and other related examinations to clarify the cause of the disease. For patients who are not diagnosed with diabetes, if the postprandial blood glucose is 15.0mmol/L, they are considered to have diabetes. If diagnosed, the patient needs to be treated with medication under the guidance of a professional doctor. The urine ketone bodies should also be further checked and the pH of the blood should be checked to determine whether diabetic ketoacidosis has occurred. If a diabetic patient’s blood glucose is at 15.0 mmol/L, it is possible that the diet is not well controlled, or there is heavy physical labor, or glucose-lowering drugs are not taken in a timely manner, etc. Patients should try to circumvent such situations. If a diabetic patient’s blood glucose continues to be 15.0mmol/L, it is easy for various types of acute infections to occur. Since high blood glucose is the best culture medium for these microorganisms, it is more difficult to cure them, thus patients should immediately undergo anti-infection treatment if they have infections or fever to avoid complications. In addition, patients should try to control blood glucose at the standard state, i.e. fasting blood glucose below 7.5mmol/L and two hours after meal blood glucose below 8.5mmol/L, in order to minimize the fluctuation of blood glucose and avoid the high level of blood glucose. Elevated blood glucose is very detrimental to the patient’s glucose metabolism, lipid metabolism, protein metabolism and trace element metabolism.