Fasting blood glucose 12.7mmol/l is more likely to consider diabetes mellitus, but do not rule out other special circumstances, such as stress hyperglycemia, medication hyperglycemia and so on. 1. Diabetes mellitus: diabetes mellitus can be diagnosed when fasting blood glucose ≥7.0mmol/L is accompanied by diabetes mellitus symptoms, which include the typical symptoms of three more and one less, such as drinking, eating, urinating and weight loss, and there may be fatigue, skin dryness, and difficulty in wound healing. 2. Stress hyperglycemia: In case of illness or trauma, blood sugar may rise transiently, which is called stress hyperglycemia, and blood sugar usually returns to normal after the illness or trauma is cured. 3. Pharmacological hyperglycemia: If you are using certain glucose-raising drugs, such as glucocorticoids and growth hormone, your blood sugar may rise, and after you stop using the glucose-raising drugs for a period of time, your blood sugar will usually return to normal, or you may develop diabetes mellitus. Fasting blood glucose 12.7mmol/ suggest endocrinology consultation, further improve the glucose tolerance test, glycated hemoglobin and other tests to clarify the diagnosis.