Whether or not 10mmol/L preprandial blood glucose is considered high depends on whether or not the value is a fasting blood glucose or a random blood glucose. If 10mmol/L is fasting blood sugar, it is considered elevated fasting blood sugar and further examination by a doctor is recommended. If it is a random blood glucose, it is within the normal range. Under normal circumstances, fasting blood glucose is 3.9-6.1 mmol/L; random blood glucose should be <11.1 mmol/L; 2-hour postprandial blood glucose should be <7.8 mmol/L. Fasting blood glucose for type 1 and type 2 diabetic patients should be around 4.4-7.0 mmol/L; non-fasting blood glucose target is <10.0 mmol/L. If the patient himself has diabetes symptoms and belongs to the fasting blood glucose, then the diagnosis of diabetes can be made, and the patient is recommended to consult the endocrinology department in time.