Blood sugar is high, through the control of diet and exercise for a week of time to drop range has not yet uniform data, the specific can drop how much varies from person to person, it is recommended to consult a doctor. Normal fasting blood glucose reference range is 3.9~6.1mmol/L, and normal two-hour postprandial blood glucose should be less than 7.8mmol/L. When the fasting blood glucose is greater than or equal to 6.1mmol/L but less than 7.0mmol/L and the two-hour postsugar load blood glucose is less than 7.8mmol/L, it suggests that the fasting blood glucose is impaired. When fasting blood glucose is less than 7.0 mmol/L but 2-hour post glycemic load blood glucose is greater than or equal to 7.8 mmol/L and less than 11.1 mmol/L, it suggests impaired glucose tolerance. If you are in the pre-diabetic stage, it is recommended to control your blood glucose through dietary control and moderate exercise. If your blood glucose is still poorly controlled, it is recommended to take medication under the guidance of a doctor.