Source-checked
Liver
Total bilirubin
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This is the date the draft was written, not a medical review date.
The sum of unconjugated (indirect) and conjugated (direct) bilirubin, the end product of haem breakdown. Jaundice becomes clinically visible at roughly 2 to 3 mg/dL (about 34 to 51 µmol/L).
Reference interval
| Conventional (mg/dL) | SI (µmol/L) | |
|---|---|---|
| Adults | 0.1–1.2 mg/dL | 1.7–20.5 µmol/L |
Specimen: Serum (protect from light) · Conventional × 17.1 = SI
Causes of high values
Haemolysis, ineffective erythropoiesis, Gilbert and Crigler-Najjar syndromes, neonatal physiological jaundice (unconjugated); hepatitis, cirrhosis, Dubin-Johnson syndrome, intra- and extrahepatic cholestasis (mainly conjugated).
Causes of low values
Not clinically significant.
Pre-analytical and method notes
Bilirubin is photolabile, so exposed samples read falsely low. Neonatal reference intervals and treatment thresholds are age-in-hours dependent and are not covered by the adult interval shown. Reference intervals vary by laboratory, method and population; use the interval printed on the report.
References
- Rifai N, Horvath AR, Wittwer CT. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Elsevier, 6th edition (2018) — Tier 3 (textbook)
- McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. Elsevier — Tier 3 (textbook)
- Loscalzo J, et al.. Harrison's Principles of Internal Medicine. McGraw-Hill, 21st edition (2022) — Tier 3 (textbook)
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