Jaundice (yellow skin or eyes)

Jaundice (icterus) appears when blood bilirubin exceeds ~3 mg/dL (50 µmol/L). The yellow pigment is bilirubin itself — a breakdown product of haemoglobin — and its accumulation reflects a problem somewhere in the chain from red-cell destruction → liver conjugation → biliary excretion. The clinical work-up sorts the cause into three categories based on which bilirubin fraction is elevated and which other liver markers move:

• Pre-hepatic (haemolysis): mostly indirect bilirubin up, haptoglobin low, LDH up, reticulocytes up.
• Hepatic (hepatitis, cirrhosis, Gilbert): mixed bilirubin pattern, ALT/AST very high in acute hepatitis or modestly up with Gilbert syndrome.
• Post-hepatic (gallstones, pancreatic head tumour, primary sclerosing cholangitis): direct bilirubin up, alkaline phosphatase and GGT markedly up, often pale stools + dark urine.

• Viral hepatitis — A, B, C, E; commonest acute hepatic cause worldwide.
• Alcohol-related liver disease, NAFLD/NASH — chronic hepatic.
• Gilbert syndrome — benign genetic; mild and intermittent.
• Gallstone in the common bile duct (choledocholithiasis) — post-hepatic with abdominal pain.
• Pancreatic head cancer — painless progressive jaundice, classically with weight loss.
• Drug-induced liver injury — many drugs (paracetamol overdose, antibiotics, statins, herbal remedies).
• Haemolytic anaemia — pre-hepatic; jaundice without dark urine.
• Neonatal jaundice — physiologically common in newborns; not relevant to adults.

First-line: total + direct bilirubin (so the indirect fraction can be calculated), ALT, AST, ALP, GGT, albumin, INR (synthetic function), CBC + reticulocyte count, haptoglobin, LDH. Add viral hepatitis serology (HAV IgM, HBsAg + anti-HBc IgM, anti-HCV) and abdominal ultrasound if pattern suggests hepatic or post-hepatic cause. Mediora.AI interprets the pattern across these markers.