Creatinine Test Price in Rasulgarh

Test Description

Serum Creatinine is the most widely used biochemical marker of renal filtration function. Creatinine is an endogenous metabolite produced at a relatively constant rate from the non-enzymatic breakdown of phosphocreatine in skeletal muscle. It is freely filtered at the glomerulus with minimal tubular reabsorption (approximately 10–15% undergoes tubular secretion). Serum creatinine is inversely related to the glomerular filtration rate (GFR); doubling of serum creatinine corresponds roughly to a 50% loss of GFR. Normal range: Males 0.7–1.3 mg/dL; females 0.5–1.1 mg/dL. Serum creatinine is used to estimate GFR using validated equations such as CKD-EPI or MDRD, enabling CKD staging (Stages 1–5). Elevated creatinine indicates renal impairment from pre-renal (dehydration), intrinsic renal (glomerulonephritis, acute tubular necrosis, interstitial nephritis), or post-renal (obstructive uropathy) causes. Limitations include influence by muscle mass (athletes have higher, elderly and malnourished individuals have lower creatinine), and late rise in acute kidney injury (creatinine rises only after ~50% nephron loss). Cimetidine and trimethoprim inhibit tubular creatinine secretion and can artificially raise serum creatinine without affecting true GFR.