glycosuria n : the presence of abnormally high levels of sugar in the urine

Glycosuria or glucosuria is an abnormal condition of osmotic diuresis due to excretion of glucose by the kidneys.

The most common cause of glycosuria is untreated diabetes mellitus. This disease raises plasma glucose levels far above normal, and beyond a certain threshold, the excess glucose is excreted by the kidneys, taking water with it and producing diuresis. The threshold varies somewhat from one individual to another, with values around 8.9 - 10 mmol/l (160 - 180 mg/dl). As a reference, the normal blood value of fasting glucose is around 3.9 - 5.8 mmol/l (70 - 105 mg/dl).

This point is called the renal threshold of glucose (RTG) . Some people, especially children and pregnant women, may have a low RTG (less than ~7 mmol/L glucose in blood to have glucosuria).

If the RTG is so low that even normal blood glucose levels produce the condition, it is referred to as renal glycosuria.

References

See also

• Renal glycosuria