Liver Function Tests (LFT)

Hepatobiliary

Pattern recognition — hepatocellular vs cholestatic vs mixed.
ASTALTALPGGTBilirubin (T/D)AlbuminPT/INR

Hepatocellular pattern (ALT/AST ≫ ALP)

Common causes

  • • Viral hepatitis
  • • Drug/Toxin (paracetamol)
  • • Alcohol
  • • NAFLD
  • • Autoimmune hepatitis
  • • Ischaemic hepatitis

Significance: ALT >1000 suggests viral/drug/ischaemic; AST:ALT >2 suggests alcohol.

Differential diagnosis

  • • Acute viral hepatitis
  • • Paracetamol toxicity
  • • AIH
  • • Wilson disease

Next investigations

  • • HBsAg, anti-HCV, IgM anti-HAV/HEV
  • • Paracetamol level
  • • USG abdomen
  • • ANA, ASMA, IgG

Red flags

  • • INR >1.5 + encephalopathy = acute liver failure
  • • Rising bilirubin with falling transaminases

Cholestatic pattern (ALP/GGT ≫ ALT)

Common causes

  • • Biliary obstruction
  • • PBC / PSC
  • • Drug-induced
  • • Infiltrative disease

Significance: Identify intra- vs extra-hepatic — USG first.

Differential diagnosis

  • • Choledocholithiasis
  • • Pancreatic head ca
  • • Cholangitis
  • • PBC

Next investigations

  • • USG abdomen
  • • MRCP
  • • AMA (for PBC)
  • • Tumour markers (CA 19-9)

Red flags

  • • Charcot triad (fever, jaundice, RUQ pain) = cholangitis
  • • Painless jaundice + weight loss

Educational support only — not a substitute for clinical judgment.

WardRound

WardRound

Clinical Decisions in Seconds