Creatinine

Creatinine is a breakdown product of muscle that is usually produced at a fairly constant rate by the body (depending on your muscle mass). It is filtered by the kidney. If the filtering of the kidney is deficient blood levels rise. This effect is used as an indicator of renal function. Creatinine is a simple test and it is the most commonly used indicator of renal function. It should be remembered that rise in blood creatinine levels is observed only with marked damage to functioning nephrons; therefore this test is not suitable for detecting early kidney disease. A much better estimation of kidney function gives the creatinine clearance test[?].