Fasting blood glucose of 5.7mmol/L is generally not a precursor to diabetes. Fasting blood glucose is required overnight fasting 8 to 10 hours under the circumstances of the measurement of blood glucose concentration, the normal range of 3.9 ~ 6.1mmol / L, so fasting blood glucose 5.7mmol / L belongs to the normal range, indicating that the blood glucose value is normal. However, if the fasting blood glucose exceeds 6.1mmol/L or the two-hour postprandial blood glucose exceeds 7.8mmol/L, you need to be alert to the possibility of pre-diabetes or diabetes. It is recommended that you visit a doctor if you have abnormal blood glucose levels.