What is creatinine clearance, and how is it different from serum creatinine?

Creatinine clearance measures the rate at which your kidneys clear creatinine from the blood and is a more comprehensive assessment of kidney function than serum creatinine alone. Creatinine clearance requires both a blood sample and a 24-hour urine collection, whereas a serum creatinine test only measures the amount of creatinine in your blood. The clearance test provides insight into how efficiently your kidneys are filtering waste, making it useful for detecting early kidney damage or monitoring chronic kidney disease (CKD).