Glucose is a type of sugar that serves as the body’s primary energy source. Normally, glucose is filtered by the kidneys and reabsorbed into the bloodstream, leaving little to no glucose in the urine. When glucose appears in urine—a condition known as glucosuria—it indicates that blood sugar levels are elevated beyond the kidneys' ability to reabsorb it.
Testing for glucose in urine helps identify conditions such as diabetes, impaired glucose regulation, and, in rare cases, kidney disorders affecting glucose reabsorption.