The microalbumin/creatine ratio measures the tiny amounts of albumin that the body begins to release into the urine several years before significant kidney damage becomes apparent. Albumin, a protein produced in the liver, is present in high concentrations in the blood, but when the kidneys are functioning properly, virtually no albumin is allowed to leak through into the urine. Creatinine, a byproduct of muscle metabolism, is usually excreted into the urine on a consistent basis. Creatinine’s level in the urine is relatively stable. Since the concentration (or dilution) of urine varies throughout the day, this property of creatinine allows the measurement to be used as a corrective factor in random/spot urine samples.