Fasting blood glucose 6.2mmol/L in the morning is not very high and not dangerous. The normal value of fasting blood glucose is 3.9-6.1 mmol/L. The blood glucose criteria for the diagnosis of diabetes mellitus: fasting blood glucose ≥ 7.0 mmol/L, or 2-hour post glycemic load blood glucose ≥ 11.1 mmol/L, or random blood glucose ≥ 11.1 mmol/L. Glycemic criteria for the diagnosis of gestational diabetes mellitus: fasting blood glucose greater than or equal to 5.1 mmol/L at 24-28 weeks of gestation and after 28 weeks of gestation; 1h blood glucose greater than or equal to 10.0 mmol/L after 75g glucose and 2h blood glucose greater than or equal to 8.5 mmol/L. Normal morning fasting blood glucose 6.2mmol/L is slightly high, it is recommended to review the blood glucose, still high recommended timely medical care. If diabetic patients, fasting blood glucose 6.2mmol / L, blood glucose control standards. If gestational diabetes, fasting blood glucose 6.2mmol / L is a little high, it is recommended to adjust the medication under the guidance of a doctor. Fasting blood sugar 6.2mmol/L is recommended to clarify the situation under the guidance of a doctor.