About Glucose (Urine)
Glucose in the urine (glucosuria) occurs when blood glucose exceeds the kidney's reabsorption threshold (typically around 180 mg/dL), causing sugar to spill into the urine. It is a classic sign of uncontrolled or undiagnosed diabetes; a positive urine glucose on a routine urinalysis should always prompt a fasting blood glucose and HbA1c. A rare exception is SGLT2 inhibitor medication, which intentionally lowers the kidney threshold to cause glucosuria as a therapeutic mechanism.