Urine is the waste product of the kidney, which has a selective permeability that allows the removal of unwanted residues in our body and the retention of substances that we do not want to be excreted. The kidney has a kind of function that filters and cleanses the blood.
Excess of any substance in the urine indicates that the substance is more than desired in the blood. It means that there is a metabolic disorder associated with this substance. Also, some cell types call attention to problems in the bladder and urinary tract.