Glucose In The Urine
by Joseph D. Tabora, M.D.
This article starts below.
The presence of glucose in the urine, or glucosuria, means that the blood glucose level has exceeded the level at which the kidneys can reabsorb glucose.
Glucose is a prime commodity of the body. It is the source of energy for all cells. This is why glucose is never present in the urine. Glucose that passes through the filters of the kidney (glomeruli) and bound to be passed out with urine are reabsorbed by the kidney tubules and returned to the blood. This reabsorption of glucose keeps this valuable substance out of the urine.
Unfortunately, the ability of the kidney to reabsorb glucose is limited. Beyond a certain level of blood sugar, the reabsorbtive capacity of the kidney is surpassed, and glucose begins to spill in the urine. The presence of glucose in the urine implies that the renal threshold of glucose reabsorption has been exceeded. Symptoms of diabetes mellitus, especially osmotic diuresis, becomes apparent when glucose becomes present in the urine.