Diabetes mellitus 20 points, both fasting blood sugar or 2 hours after meal blood sugar, are more serious, if no longer active treatment, it is easy to trigger diabetic ketoacidosis, and even life-threatening. The current adult fasting blood glucose normal value standard is 3.9~6.1mmol, 2 hours after meal blood glucose<7.8mmol/L. Blood glucose for 20mmol/L has exceeded the normal value of three times, belongs to the more serious, due to the body’s glucose utilization obstacle, the blood glucose is very high, it is easy to lead to diabetic ketoacidosis, or hyperosmolar hyperglycemia syndrome, which will endanger the life. Patients should pay attention to the abnormal blood glucose, actively go to the regular hospital for diagnosis and treatment, improve the glycated hemoglobin test, and further monitor the blood glucose changes, and timely adjust the glucose lowering program, so as not to lead to serious consequences.