Glycosuria occurs when:

Glycosuria occurs when:

• A. Blood glucose exceeds renal threshold for glucose reabsorption
• B. Blood glucose below renal threshold
• C. Urine glucose below threshold
• D. Urine glucose above serum threshold

Answer: (A)

Glycosuria occurs when the amount of glucose filtered by the kidneys exceeds the proximal tubule’s capacity to reabsorb it. The tubules reclaim glucose up to a limit called the renal threshold for glucose reabsorption. If blood glucose stays below that threshold, all filtered glucose is reabsorbed and urine glucose is absent. When blood glucose rises above the threshold, the transport mechanisms saturate, and the excess glucose spills into the urine. This situation is commonly seen with uncontrolled diabetes mellitus, where hyperglycemia drives the filtered glucose load past the reabsorptive capacity.

Glycosuria occurs when the amount of glucose filtered by the kidneys exceeds the proximal tubule’s capacity to reabsorb it. The tubules reclaim glucose up to a limit called the renal threshold for glucose reabsorption. If blood glucose stays below that threshold, all filtered glucose is reabsorbed and urine glucose is absent. When blood glucose rises above the threshold, the transport mechanisms saturate, and the excess glucose spills into the urine. This situation is commonly seen with uncontrolled diabetes mellitus, where hyperglycemia drives the filtered glucose load past the reabsorptive capacity.