Blood creatinine is a commonly used clinical indicator to monitor renal function. Creatinine in normal human blood consists of both exogenous and endogenous sources. By monitoring blood creatinine values, the staging of renal function can be evaluated. Blood creatinine can be described clinically by μmol/L or mg/dl. The conversion between μmol/L and mg/dl is 1 mg/dl equals 88.4 μmol/L. The current international common unit is μmol/L. The normal value of blood creatinine is 53-106 μmol/L for men; 44-97 μmol/L for women.