Sugar In Urine

Sugar in urine (glycosuria professionally) means more precisely presence of glucose in urine. It is definitely not a normal sign and it usually indicates a pathologic condition. In principle, when there is a physiological concentration of blood sugar, only a minimal amount of glucose gets into urine during kidney filtration and this small amount is reabsorbed before urine fluid leaves kidney to further parts of urinary tract. Therefore, if we find sugar in urine, it means that its blood level is abnormally high or that it is not reabsorbed into blood by kidney tissue.



Untreated or inadequately treated diabetes is associated with an increase in glucose serum level. Larger amount of sugar is then filtered in kidney and we find it in urine. Glucose presence in urine must always lead to suspicion of diabetes and to further examination to confirm or rule out this disease.


In many women in any stage of pregnancy sugar in urine may appear. These women should be investigated and regularly checked for possible development of gestational diabetes.

Benign glycosuria

This is a very rare disease, when kidneys are unable to reabsorb glucose molecules properly and it is found in urine even if blood glucose level is normal. However, these glucose losses are not usually significant, this condition is not dangerous and it doesn’t bring such complications like in diabetes.


Complications are mainly related to considerable losses of blood glucose into urine in diabetes. The presence of sugar in urine increases the risk of urinary tract infection, because sugar is a welcomed nutrient for bacterial microorganisms. Sugar molecules lost into the urine take water and ions along. This situation leads to dehydration and loss of minerals. For this reason, untreated diabetes typically manifests by excessive urination and unusually strong thirst.

Diagnostic approach

The basis is, of course, urinalysis. Firstly, using test strips for basic orientation is made; more precise is examination of urine chemical composition in a laboratory. Part of the examination should be microbiological screening to rule out significant bacterial presence. When there is glucose found in urine, there always must be serum level of glucose checked.

Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources