MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Renal Function

Urea:Creatinine Ratio

July 6th, 2018


In the presence of raised creatinine, urea disproportionately higher than creatinine suggests a prerenal cause such as hypovolaemia, heart failure or shock.
  • Interpretation

  • Elevated ratio: >100:1
  • Reduced ratio: <40:1

Elevated Urea:Creatinine Ratio

A urea:creatinine ratio >100:1 is commonly used as a marker of prerenal renal failure. Any cause of isolated urea elevation may also elevate the ratio.
  • Causes of Elevated Urea:Creatinine Ratio

  • Prerenal renal failure - hypovolaemia, sepsis, renal venoconstriction
  • Dehydration
  • Protein load - GI bleed (especially upper GI), high protein diet
  • Catabolic state - trauma, sepsis, starvation, corticosteroids

Reduced Urea:Creatinine Ratio

  • Causes of Reduced Urea:Creatinine Ratio

  • Severe liver failure
  • Low protein intake - low protein diet, malnutrition, malabsorption, alcoholism
  • Muscle breakdown - body building, rhabdomyolysis
  • Pregnancy
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...