Bilirubin Physiology

Laboratory Assay of Bilirubin

Etiology of Hyperbilirubinemia (see also Elevated Liver Function Tests)

Unconjugated (Indirect) Hyperbilirubinemia

Increased Bilirubin Production

  • Dyserthropoiesis
    • Primary Shunt Hyperbilirubinemia (Idiopathic Dyserythropoietic Jaundice)
  • Hematoma
  • Hemolytic Anemia (Extravascular/Intravascular) (see Hemolytic Anemia)

Impaired Hepatic Bilirubin Uptake

Impaired Bilirubin Conjugation

Conjugated (Direct) Hyperbilirubinemia

Inherited Disorders

  • Rotor Syndrome (see Rotor Syndrome)
    • Physiology: defective sinusoidal reuptake of conjugated bilirubin
  • Dubin-Johnson Syndrome (see Dubin-Johnson Syndrome)
    • Physiology: defective canalicular organic anion transport

Intrahepatic Cholestasis


Graft vs Host Disease (GVHD) (see Graft vs Host Disease)

Hemochromatosis (see Hemochromatosis) Hepatic Infiltration

Hepatic Veno-Occlusive Disease (VOD) (see Hepatic Veno-Occlusive Disease) Intrahepatic Cholestasis of Pregnancy (see Pregnancy) Ischemic Hepatitis (Hypoxic Hepatitis, Shock Liver) (see Ischemic Hepatitis)

  • Physiology: hepatic hypoperfusion

Non-Alcoholic Fatty Liver Disease (NAFLD) (see Non-Alcoholic Fatty Liver Disease) Post-Liver Transplant (see Liver Transplant) Pre-Eclampsia (see Pre-Eclampsia, Eclampsia) Primary Biliary Cirrhosis (PBC) (see Primary Biliary Cirrhosis) Reye Syndrome (see Reye Syndrome) Sepsis (see Sepsis)

  • Physiology
    • Hepatic Hypoperfusion

Sickle Cell Disease (Hepatic Crisis) (see Sickle Cell Disease)

Extrahepatic Cholestasis (Biliary Obstruction)

Clinical Manifestations

Gastrointestinal/Hepatic Manifestations