Under normal circumstances, fasting blood glucose concentration should be 3.9-6.0mmol/L, but blood glucose between 2.8-3.9mmol/L is low blood glucose, not low blood glucose, below 2.8mmol/L is low blood glucose. Blood sugar between 6.0-7.0 mmol/L is considered high blood sugar and not diabetes, and it is only diabetes when it reaches or exceeds 7.0 mmol/L. Blood glucose in pregnancy has additional requirements, if it is checked between 22-26 weeks of gestation, the normal blood glucose range should be between 3.9-5.0mmol/L, and reaching or exceeding 5.1mmol/L is to be considered as gestational diabetes mellitus. Fasting blood glucose is high, need to do further islet function test, determine the type of diabetes, so as to choose further treatment measures.