Urine sugar is not necessarily a sign of diabetes, but can also be seen in other conditions, such as eating too much sugar. Under normal circumstances, urine does not appear positive for urine sugar, but when there are dietary irregularities, such as eating too much sugary food or drinking too many sugary drinks, the phenomenon of urine sugar can occur. The diagnosis of diabetes mellitus is based on the typical symptoms of “three more and one less” (drinking more, urinating more, eating more, and losing weight) plus the measurement of venous plasma glucose ≥11.1mmol/L, fasting blood glucose ≥7.0mmol/L, or 2-hour glucose ≥11.1mmol/L after glucose tolerance test at any time of the day, which can be diagnosed as diabetes mellitus if one of them meets the standard. One of them is enough for a diagnosis of diabetes mellitus. China’s 2020 guidelines for the prevention and treatment of type 2 diabetes include glycated hemoglobin in the diagnostic criteria, and glycated hemoglobin ≥6.5% can be used as an additional diagnostic criterion for diabetes, but diabetes cannot be ruled out if it is lower than 6.5%. In short, the appearance of urine sugar, should promptly go to the hospital, improve the relevant examination, under the guidance of the doctor for treatment.