The word Creatinine is derived from a Greek word that means ‘flesh'. From human body creatinine is passed out through urine and Creatinine Levels in Urineis checked in any standard urine drug test. Basically creatinine is produced from a substance called cratine phosphate. Creatine phosphate is present in human muscles and some part of creatine constantly separates from human muscles thus producing creatinine constantly. The amount of creatine produced by human body depends on the mass of muscles. So, the Creatinine Levels in Urinevaries from person to person as the muscle mass of each human being is different.

In the chemical language we can say that creatinine is a cyclic product which is derived from creatine. After a certain limit the level of creatinine in blood is harmfulfor human body so it needs to be filtered out. Thus the main body part which deal with decreasing creatinine level in blood is kidney. The creatinine from blood is excreted along with urine. So in order to check proper functioning of kidney, to basic method adopted is to check Creatinine Levels in Urine. In case the creatinine level is very high or very low then it indicates that glomerular filter rate is not good. Improper glomerular rate that is GRF directly indicates the functioning of human renal system. The creatinine level in blood and urine is calculated and if they both are not proportional, it indicated problem with renal system. Generally men have higher muscle mass than women so they have higher creatinine level in blood and urine than women. Similarly the vegetarians have lesser creatinine level in blood and urine than non-vegetarians.

The level of creatinine in serum is not very reliable because it do not indicate any problem in early stage of renal or kidney disease. This test show results only when there is some measurable damage to the nephrons which is the functional unit of kidney. Creatinine clearance test is very efficient as apart from estimating its level in urine it also can estimate a person's age, sex, race etc. the creatinine clearance test will give correct results only when the sample is not diluted and when the test is conducted within 24 hours after taking the sample. A lower creatinine level may indicate an obstruction in urinary tract, kidney infection, excessive meat diet, kidney failure or reduced blood flow to kidney etc. This is the whole discription about it.