Glucosuria or Glycosuria

The sodium-glucose symporters can reclaim about 300mg glucose/min. 

If glomerular filteration is normal, the renal threshold for glucose is a plasma concentration of about 200mg/ml. 

When the blood concentration of glucose is above this level, the symporters cannot work fast enough to reabsorb it all, and the excess glucose remains in the urine. this condition is called glucosuria or glycosuria. 

The most common cause of glucosuria is diabetes mellitus, in which blood glucose level may rise far above normal because insulin activity is deficient. 

Another cause of glucosuria is a rare genetic defect in the sodium-glucose symporter that greatly reduces its tm. In these cases, glucose appears in the urine even through the blood glucose level is normal.