Bilirubin is a waste product formed when red blood cells break down. Your liver processes it and removes it via bile. A high bilirubin can point to a liver or bile problem, but the most common cause of a mildly raised value is completely harmless: Gilbert syndrome.
Below you will read what bilirubin measures, when it points to jaundice, and why a mild elevation is often no problem.
What is bilirubin?
When old red blood cells break down, bilirubin is released. The liver makes it water-soluble (conjugation) and excretes it in bile. Bilirubin gives bile and stool their colour. If it builds up in your blood, your skin or the whites of your eyes can turn yellow.
Direct and indirect bilirubin: the difference
A measurement often distinguishes two forms, which helps your doctor locate the cause:
- Indirect (unconjugated) bilirubin - raised with accelerated breakdown of blood cells or with Gilbert syndrome.
- Direct (conjugated) bilirubin - raised with liver or bile duct problems, such as gallstones or cholestasis (Kwo et al., 2017).
The separate value for direct bilirubin helps distinguish a blood, liver or bile cause.
Gilbert syndrome: often the harmless explanation
Gilbert syndrome is a common, inherited variant in which the liver processes bilirubin a little more slowly. An estimated substantial proportion of the population has this variant. It is benign and needs no treatment (Strassburg, 2010). The value often rises during fasting, illness or stress, and then falls again.
Notably, a mildly elevated bilirubin, as in Gilbert, is actually associated in research with a lower risk of cardiovascular disease, possibly due to the antioxidant action of bilirubin (Vítek, 2012).
When does bilirubin point to jaundice?
At strongly elevated values, jaundice can occur: yellow skin or eyes, dark urine and sometimes pale stools. That always deserves assessment by a doctor, especially when it accompanies other abnormal liver values. A complete explanation is in understanding liver values.
What can you do about high bilirubin?
If the cause is Gilbert, reassurance is usually enough. With other causes, the approach depends on the underlying reason, which your doctor determines. Want a picture of your values? The Vital Check liver function test measures bilirubin among others, with review by a doctor.
Frequently asked questions
Is a mildly elevated bilirubin dangerous?
Usually not. A mild elevation without other abnormalities often points to benign Gilbert syndrome. With higher values or accompanying symptoms, assessment is needed.
Can fasting raise my bilirubin?
Yes, in people with Gilbert, bilirubin often rises during fasting or illness. That is a known and harmless phenomenon.
Do yellow eyes always mean a liver problem?
Not always, but it does deserve assessment. Yellowing of the skin or eyes can point to a liver, bile or blood cause and should be examined by a doctor.
References
- Strassburg CP. Hyperbilirubinemia syndromes (Gilbert-Meulengracht, Crigler-Najjar, Dubin-Johnson, and Rotor syndrome). Best Practice & Research Clinical Gastroenterology. 2010. PubMed
- Vítek L, et al. The role of bilirubin in diabetes, metabolic syndrome, and cardiovascular diseases. Frontiers in Pharmacology. 2012. PubMed
- Kwo PY, et al. ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries. American Journal of Gastroenterology. 2017. PubMed
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