The highest value of blood sugar in a normal person is about 11.1mmol/L. If the blood sugar exceeds 11.1mmol/L it means that you have diabetes. Under normal circumstances, fasting blood glucose will not exceed 6.1mmol/L, blood glucose two hours after meal will not exceed 7.8mmol/L, blood glucose one hour after meal will not exceed 11.1mmol/L, and blood glucose three hours after meal will return to the normal fasting state, and it will not exceed 6.1mmol/L. If the patient is diabetic, there is basically no floor for the elevation of blood glucose, and in diabetic ketoacidosis and tumor In clinical observations of patients, blood glucose can be as high as 30-40 mmol/L, partially unmeasurable using machines. Hyperglycemia can cause great harm to the body, and even lead to sudden death, it is recommended that diabetic patients actively regulate blood glucose to avoid complications. Usually should be coarse grains, low-sugar food, in order to effectively reduce blood glucose, more exercise, such as aerobic exercise can be moderate, to reduce blood glucose has a certain degree of help.