The blood glucose standard adopted in 2021 is still that if the fasting blood glucose is more than 7.0 mmol/L, the random blood glucose or two hours after meal blood glucose is more than 11.1 mmol/L to reach the blood glucose diagnostic criterion of diabetes mellitus. Diagnostic criteria for diabetes mellitus: diabetes mellitus can be diagnosed if fasting blood glucose ≥ 7.0 mmol/L, or two-hour post glycemic load blood glucose ≥ 11.1 mmol/L, or random blood glucose ≥ 11.1 mmol/L, accompanied by three more and one less symptom (more drinking, eating, urinating, and weight loss). The diagnosis of diabetes mellitus is also considered in the absence of symptoms of diabetes mellitus, with fasting blood glucose ≥ 7.0 mmol/L or blood glucose ≥ 11.1 mmol/L two hours after a meal monitored twice on non-same days. If diabetes mellitus is suspected, you can go to the endocrinology clinic of the hospital, improve the auxiliary examination under the guidance of the doctor, and give individualized treatment plan after the diagnosis is clarified.