Creatinine: A Marker of Kidney Function

Creatinine is a waste product filtered by the kidneys and is used to estimate kidney function. Learn what the value means and common ranges.

Creatinine is a waste product produced by normal muscle metabolism. It is filtered by the kidneys and excreted in urine.

Typical reference range

  • Male: 0.74–1.35 mg/dL
  • Female: 0.59–1.04 mg/dL

How it is interpreted

Creatinine is rarely interpreted alone. It is usually combined with age, sex, and body size to compute the estimated glomerular filtration rate (eGFR), a more useful indicator of kidney filtration.

Factors that may affect creatinine

  • Hydration status
  • Recent strenuous exercise
  • High dietary protein or creatine supplementation
  • Certain medications
  • Muscle mass

Creatinine is usually evaluated alongside urea/BUN, electrolytes, and urine albumin as part of a kidney function panel.