Causes of high fasting blood glucose include physiological and pathological, physiological such as stress, infection, etc. Pathological seen in diabetes mellitus, etc., and can be controlled by using hypoglycemic drugs to control blood glucose. 1. Physiological: mostly seen in stress, infection, emotional tension, etc., blood glucose can be transiently elevated, and after the removal of the trigger, blood glucose can return to normal. 2. Pathological: common in diabetes, when the fasting blood glucose value is high, you need to improve the glycated hemoglobin, glucose tolerance test and other tests under the guidance of the doctor, a clear diagnosis, you can use hypoglycemic drugs under the guidance of the doctor to control blood glucose. There are many reasons for elevated fasting blood sugar, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor to check and treat.