Why should human urine sample not contain glucose at all?

Human urine should not contain glucose because, under normal physiological conditions, the kidneys reabsorb glucose from the filtrate back into the bloodstream. The presence of glucose in urine, known as glucosuria, typically indicates that blood glucose levels are elevated, surpassing the renal threshold for glucose reabsorption, which can occur in conditions like Diabetes mellitus. Therefore, glucose in urine is often a sign of a metabolic disorder that requires medical attention.