bilirubin

American  

[bil-uh-roo-bin, bil-uh-roo-bin] / ˈbɪl əˌru bɪn, ˌbɪl əˈru bɪn /

noun

Biochemistry.

1. a reddish bile pigment, C 33 H 36 O 6 N 4 , resulting from the degradation of heme by reticuloendothelial cells in the liver: a high level in the blood produces the yellow skin symptomatic of jaundice.

---

bilirubin British  

/ ˌbɪlɪˈruːbɪn, ˌbaɪ- /

noun

1. an orange-yellow pigment in the bile formed as a breakdown product of haemoglobin. Excess amounts in the blood produce the yellow appearance associated with jaundice. Formula: C 32 H 36 O 6 N 4

---

bilirubin Scientific  

/ bĭl′ĭ-ro̅o̅′bĭn /

1. A reddish-yellow pigment that is a constituent of bile and gives it its color. Bilirubin is a porphyrin derived from the degradation of heme. It is often a constituent of gallstones, and also causes the skin discoloration seen in jaundice. Chemical formula: C ₃₃ H ₃₆ N ₄ O ₆ .

---

Etymology

Origin of bilirubin

< German Bilirubin (1864), equivalent to Latin bīli ( s ) bile + rub ( er ) red + German -in -in ²

Example Sentences

In a Phase 3 clinical trial, two patients out of a total 2,000 recorded high levels of alanine aminotransferase and bilirubin, typically a strong predictor of liver failure.

From Barron's • Apr. 15, 2026

Children are basically exposed to ultra-violet light to dissolve the excess bilirubin in their red blood cells.

From BBC • Jan. 7, 2025

This is caused by a build-up of bilirubin, a yellow substance, in the blood, meaning the babies' skins have a yellow tinge.

From BBC • Jan. 7, 2025

Typically, bilirubin is secreted into the gut where it has to be discharged.

From Salon • Jan. 4, 2024

Although the crystalline forms of h�matoidin and bilirubin are not to be distinguished, it is not to be conceded that the two substances are identical.

From A System of Practical Medicine by American Authors, Vol. I Volume 1: Pathology and General Diseases by Various