Lab

Indirect Bilirubin

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Indirect Bilirubin, Unconjugated Bilirubin, Hemolytic Jaundice, Unconjugated Hyperbilirubinemia

  • See Also
  1. Total Bilirubin
  2. Conjugated Bilirubin
  3. Jaundice
  4. Liver Function Test
  5. Liver Function Test Abnormality
  • Interpretation
  1. Normal: <1.0 mg/dl
  • Causes
  • Increased (Unconjugated Hyperbilirubinemia)
  1. Increased Bilirubin production
    1. Large heme load (e.g. large Hematoma reabsorption)
    2. Rhabdomyolysis
    3. Hyperthyroidism (Thyrotoxicosis)
    4. Hemoglobinopathy (Thalassemia, Sickle Cell Anemia)
    5. Spherocytosis
    6. Hemolytic Anemia (typically mild Hyperbilirubinemia)
      1. Autoimmune Hemolytic Anemia
      2. Drug-Induced Hemolytic Anemia
      3. RBC enzyme disorders (e.g. G6PD Deficiency, pyruvate kinase deficiency, P5'N deficiency)
    7. Ineffective Erythropoiesis (increased RBC destruction in marrow)
      1. Pernicious Anemia
      2. Lead Poisoning
      3. Iron Deficiency Anemia
      4. Myeloproliferative Disorder
  2. Defective Bilirubin conjugation
    1. Neonatal Jaundice (immature liver)
    2. Gilbert's disease
    3. Crigler-Najjar syndrome
  3. Impaired hepatic uptake of Bilirubin
    1. Medications (e.g. Gemfibrozil, Indinavir)
    2. Portosystemic shunt
    3. Hepatic congestion (e.g .CHF, liver disease)
  • References
  1. Fargo (2017) Am Fam Physician 95(3): 164-8 [PubMed]
  2. Nelson (2025) Am Fam Physician 111(1): 25-30 [PubMed]