Diabetic blood glucose of 12 mmol/L should be considered a relatively high level, but this criterion also needs to be seen in the context of the type of blood glucose. The so-called blood glucose type refers to fasting blood glucose or random blood glucose. Fasting blood glucose refers to the blood glucose value measured after 8-12 hours of fasting, while random blood glucose refers to the blood glucose value at any time other than fasting blood glucose. If the fasting blood glucose is 12mmol/L, it means that the patient’s usual blood glucose control is very poor, and the postprandial blood glucose may rise to more than 20mmol/L. If the random blood glucose is 12mmol/L, the control is not particularly ideal for young patients; if the patient is older, this blood glucose value is considered to be relatively well controlled. Therefore, the blood glucose level of 12mmol/L in diabetes needs to be judged according to different situations, whether it is a high level or not.