“Diabetes 18.9” generally refers to a diabetic patient’s blood glucose level of 18.9mmol/L. A diabetic patient’s blood glucose level of 18.9mmol/L is markedly elevated both in terms of fasting blood glucose and 2-hour postprandial blood glucose, and may be more serious. The fasting blood glucose control range for diabetic patients is 4.4~7.0mmol/L, and the 2-hour postprandial blood glucose should be controlled below 10mmol/L. Therefore, diabetic patients with blood glucose level of 18.9mmol/L is significantly elevated, which may induce acute diabetic complications such as diabetic ketoacidosis, and in severe cases, it may even be life-threatening. Diabetic patients with blood glucose 18.9mmol/L need to seek timely medical treatment.