The normal creatinine value in normal human whole blood is 88.4-176.8 umol/L, and the value of serum or plasma creatinine is 53-106 umol/L in men and 44-97 umol/L in women. creatinine is composed of both endogenous and exogenous creatinine, and endogenous creatinine is mainly due to muscle metabolites. Creatinine is often used clinically to represent the function of the kidneys because of the property that creatinine is filtered through the glomerulus and not largely absorbed from the renal tubules. When blood creatinine is elevated, it indicates a decline in kidney function, commonly in various glomerular diseases, acute renal failure or secondary glomerular diseases. Decreased blood creatinine, which is common in patients who are relatively thin or who exercise less, is generally not a cause for excessive concern and will not affect the body excessively.