When is glucose in urine?

Glucose appears in the urine under the following circumstances:

- Diabetes mellitus: Diabetes is a disorder in the body’s ability to produce or use insulin. Insulin is a hormone that is needed to transport glucose from the blood into the cells of the body. When there is not enough insulin in the body, or the cells do not respond properly to insulin, the blood glucose levels can become too high. When the blood glucose levels exceed the reabsorption capacity of the proximal convoluted tubules of the nephron (approximately 180 mg/dL), the glucose spills into the urine.

- Renal glycosuria: Renal glycosuria is characterized by the spillage of glucose into the urine despite normal blood glucose levels. It is caused by a defect in the reabsorption of glucose in the proximal convoluted tubule of the nephron.

- Certain medications and medical conditions: Some medications, such as certain diuretics, steroids, and chemotherapy drugs, can cause glucose to appear in the urine. Additionally, certain medical conditions, such as Fanconi syndrome, Cushing syndrome, and pregnancy, can also cause glycosuria.