Renal function, in
nephrology, is an indication of the state of the
kidney and its role in
renal physiology.
Glomerular filtration rate (
GFR) describes the flow rate of filtered fluid through the kidney.
Creatinine clearance rate (
CCr or
CrCl) is the volume of
blood plasma that is cleared of
creatinine per unit time and is a useful measure for approximating the GFR. Creatinine clearance exceeds GFR due to creatinine secretion, which can be blocked by
cimetidine. In alternative fashion, overestimation by older serum creatinine methods resulted in an underestimation of creatinine clearance, which provided a less biased estimate of GFR. Both GFR and C
Cr may be accurately calculated by comparative measurements of substances in the blood and urine, or estimated by formulas using just a blood test result (
eGFR and
eCCr).