Glucose in Urine

Urine usually contains a very small amount of glucose. The urine of a healthy individual contains about less than 0.1% glucose, which cannot be detected by the regular urine tests. Urine usually does not contain a high amount of sugar, as the kidneys reabsorb all the filtered glucose and return it to the bloodstream. Glucose can be found in urine, only when the level of blood sugar rises to such an extent that it exceeds the capacity of the kidneys to reabsorb it. There is a renal threshold for glucose and it is approximately 160 to 190 mg/dL. If the level of blood sugar exceeds this threshold level, the kidneys become overwhelmed and fail to reabsorb it efficiently. In such a case, urine can contain it in significant high amounts. This condition is medically known as glycosuria or glucosuria.

Glycosuria Causes

Glucose present in the bloodstream is filtered by the glomeruli of the kidneys. But, the filtered glucose is reabsorbed by the proximal renal tubules of the kidneys and is then returned to the bloodstream. This normal process can get disrupted, when its level in the bloodstream is so high that the kidneys fail to reabsorb all glucose and hence, it begins to spill into the urine. So, conditions that can cause the blood its level to increase significantly can lead to glycosuria. Another possible cause is the inability of the renal tubules to reabsorb it efficiently, even when the level of blood sugar is normal.

Elevated blood sugar or hyperglycemia can be caused by conditions like, diabetes mellitus. This is the reason why, this condition is considered as a sign of diabetes. In diabetes, the body cells fail to absorb and utilize glucose from the bloodstream, either due to the deficiency of insulin or an inability to respond to insulin. As a result, the level of blood sugar increases, and sugar starts to pass into the urine. Along with diabetes, there are certain other conditions that can cause hyperglycemia and then glycosuria. Such conditions include, Cushing's syndrome, thyrotoxicosis and acromegaly.

Sometimes, glycosuria can be associated with benign conditions like, eating a heavy meal or eating a large amount of sugary foods. Even emotional stress can increase the level of sugar cose in blood and urine. Hyperalimentation too can cause the blood glucose to rise and exceed the level of renal threshold. On the other hand, renal glycosuria is the condition where the kidneys fail to reabsorb it completely, even when the level of blood sugar is normal. This condition can be associated with kidney problems, Fanconi's syndrome, Wilson's disease, cystinosis, hereditary tyrosinaemia, heavy metal poisoning, Lowe's syndrome and interstitial nephritis.

Glycosuria During Pregnancy

Presence of a small amount of glucose in the urine during pregnancy can be normal. The renal threshold gets reduced during pregnancy, for which its small amount can spill into the urine. A reduced renal threshold during pregnancy can be associated with increased renal flow. However, consistent glycosuria indicates gestational diabetes. Gestational diabetes can cause high blood glucose levels during pregnancy. It is a type of diabetes that some women develop during pregnancy.

The presence of sugar in urine is detected with the help of dipstick test. As glycosuria can be caused by so many factors, it can be treated only after ascertaining the underlying causes. If diabetes is the cause of glycosuria, then it can be treated with insulin and lifestyle and dietary modifications. The treatment options for glycosuria can vary significantly, depending on the exact causes. So, if you observe your urine glucose levels to be consistently high, then consider to get the condition properly evaluated with the help of a physician.