Bilirubin is a yellowish pigment found in your bile. It’s a by-product made when your red blood cells break down. Usually, your body removes bilirubin from the bloodstream via your liver. Then, it's converted into a substance that passes through your poo, giving it its brown colour. Learn more about the normal ranges and how to check your levels.
The normal range for bilirubin is 0-24 umol/L.
A bilirubin test alone can’t diagnose a liver or other health condition. Your GP will consider any previous or additional blood test results, lifestyle, and medical history to make a diagnosis.
When bilirubin levels are higher than normal, it’s called hyperbilirubinemia. It's usually a sign that your body isn’t clearing bilirubin from your blood effectively or that your red blood cells are breaking down faster than your body can. How your body transports the bilirubin into your poo may also be a problem.
You can check your bilirubin levels as part of a liver blood test. It’s measured along with other markers — like albumin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), globulin, total protein, and gamma-GT (GGT).
High bilirubin isn’t usually a sign of anything serious. But it's important to monitor related symptoms in case it's a sign of something more serious.
The most common symptom of high bilirubin levels is jaundice — yellowing of your skin and eyes.
Other symptoms can include:
Many health conditions can lead to high levels of bilirubin. These include:
It can also be caused by vigorous exercise — for example, if you run marathons.
If you have high bilirubin levels, your healthcare professional can help you determine the underlying cause and create a treatment plan if necessary.
There isn’t a clear link between low bilirubin and certain health conditions as more research is needed.
But some studies suggest there might be a link between low bilirubin and certain health conditions due to it’s potential antioxidant effects.
Antioxidants protect you against certain health conditions — like heart disease, eye disease, brain lesions, and stroke. But more studies are needed to confirm this.
Certain drugs can lower your bilirubin levels. These include:
Barcellini, W., & Fattizzo, B. (2015). Clinical Applications of Hemolytic Markers in the Differential Diagnosis and Management of Hemolytic Anemia. Disease markers, 2015, 635670. https://doi.org/10.1155/2015/635670.
Higuchi, S., Kabeya, Y., Uchida, J., Kato, K., & Tsukada, N. (2018). Low bilirubin levels indicate a high risk of cerebral deep white matter lesions in apparently healthy subjects. Scientific reports, 8(1), 1-5.
Karuppannasamy, D., Venkatesan, R., Thankappan, L., Andavar, R., & Devisundaram, S. (2017). Inverse association between serum bilirubin levels and retinopathy in patients with type 2 diabetes mellitus. Journal of clinical and diagnostic research: JCDR, 11(2), NC09.
Kimm, H., Yun, J. E., Jo, J., & Jee, S. H. (2009). Low serum bilirubin level as an independent predictor of stroke incidence: a prospective study in Korean men and women. Stroke, 40(11), 3422-3427.
National Health Services (2023). Itching and intraheptic cholestasis. Retrieved 10 January 2023 from https://www.nhs.uk/pregnancy/related-conditions/complications/itching-and-intrahepatic-cholestasis/.
National Health Services (2021). Jaundice. Retrieved 10 January 2023 from https://www.nhs.uk/conditions/jaundice/.
Schieffer, K. M., Bruffy, S. M., Rauscher, R., Koltun, W. A., Yochum, G. S., & Gallagher, C. J. (2017). Reduced total serum bilirubin levels are associated with ulcerative colitis. PloS one, 12(6), e0179267.
Takayanagi, R., Ohnaka, K., Kawate, H., Adachi, M., Kono, S., Morita, M., ... & Tanaka, M. (2013). Behavioral and clinical correlates of serum bilirubin concentrations in Japanese men and women.