what is blood creatinine
The creatinine blood test is used to assess kidney function. It is frequently ordered along with a BUN (blood urea nitrogen) test or as part of a basic or comprehensive metabolic panel (BMP or CMP), groups of tests that are performed to evaluate the function of the body's major organs. Blood creatinine measurements, along with age, weight, and sex, are used to calculate the estimated glomerular filtration rate (eGFR) , which is used as a screening test to look for evidence of early kidney damage. 2  Blood and urine creatinine levels may be used to calculate a creatinine clearance.