Blood test

Normal total bilirubin level in the blood

Blood test
Normal total bilirubin level in the blood

What is the normal level of total bilirubin in the blood?

Serum (in adults): 0.3 – 1.2 mg/dL

Serum (in children)

  • 0 – 1 day: 1.4 – 8.7 mg/dL
  • 1 – 2 days: 3.4 – 11.5 mg/dL
  • 3 – 5 days: 1.5 – 12.0 mg/dL

In the International System of Units (SI), total bilirubin in the blood is measured in µmol/L. The normal total bilirubin level in the SI is:

Serum (in adults): 5 – 20 µmol/l

Serum (in children)

  • 0 – 1 day: 24 – 150 µmol/l
  • 1 – 2 days: 58 – 197 µmol/l
  • 3 – 5 days: 26 – 205 µmol/l

Why normal levels can differ across different labs?

Each laboratory must establish its own normal ranges for total bilirubin in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.

Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.

Newborns are a special segment in relation to bilirubin ranges. Their normal range are very high compared with adults. The reason is that their body at the beginning is not prepared for eliminating bilirubin in feces. They reach the normal ranges for an adult about fifteen days after get birth.

What is the role of bilirubin?

Bilirubin is a brownish yellow pigment. It is considered a waste product, which gives the feces their characteristic brown color but it also has an antioxidant activity.

The 80%-85% of the daily-generated bilirubin arise from the destruction of the aged or not functional red blood cells. Red blood cells contain hemoglobin. The hemoglobin is degraded or broken into globin (the protein part), iron and heme group. A part of the heme group is the one that it is converted into bilirubin when the red blood cell is destructed. The other 15%-20% of the daily bilirubin comes from

  • Other heme proteins (myoglobin, catalase, cytochromes, peroxidase)
  • From the bone marrow by a not proper erythropoiesis

Bilirubin that comes from the heme group is called indirect bilirubin or unconjugated bilirubin. Later, part of this indirect bilirubin pass through the liver and conjugate with the glucoronic acid and it is named direct bilirubin or conjugated bilirubin.

This transformation change the water-insoluble bilirubin (unconjugated bilirubin) into a water-soluble bilirubin (conjugated bilirubin). Water-soluble bilirubin can be excreted into the bile and thus to the small intestine. Finally, part of the conjugated bilirubin is eliminated in feces and the other part is reabsorbed and eliminated in urine such as urobilinogen.

What is a total bilirubin blood test used for?

The bilirubin blood test is useful to know the liver and bile ducts functional status.

In a routine assay, only the total bilirubin is measured, but it is often asked an additional study of conjugated and unconjugated bilirubin when a concrete problem is suspected.

Many causes have an influence in the production, storage, metabolism and excretion of the bilirubin. Depending on the medical disorder, conjugated, unconjugated or both types of bilirubin can be the responsible for an increase in total bilirubin.

Hyperbilirubinemia (a high bilirubin level in the blood) can be classified into three types:

  • Pre-hepatic jaundice: Among pre-hepatic diseases with an increase in unconjugated bilirubin, we can find globular hemolytic anemias (thalassemia, sickle cell anemia), extra-globular hemolytic anemia (blood transfusion reaction), physiological jaundice and the hemolytic disease of the newborn.
  • Hepatocellular jaundice or intrahepatic: Among hepatocellular diseases with an increase predominance in conjugated bilirubin are acute and chronic viral hepatitis, hepatic cirrhosis and hepatocellular carcinoma.
  • Post-hepatic jaundice: Among post-hepatic jaundice diseases with an increase predominance in conjugated bilirubin are extrahepatic cholestasis and liver transplant rejection. There are also congenital hyperbilirubinemias such as Crigler-Najjar syndrome, Gilbert’s syndrome, Dubin-Johnson syndrome and Rotor syndrome.

If the total bilirubin level is above 2.5 mg/dl it is probably the existence of jaundice. Jaundice is a yellowing of the skin and the whites of the eyes. This is very common in newborns.

If the total bilirubin is low or near zero, it has no a clear clinical significance.

Where can I find more information about total bilirubin in the blood?

You can visit our pages about:

Which values are considered a normal total bilirubin level in the blood?

The following values are considered to be normal values:

IMPORTANT: These levels are expressed in mg/dl. They are an example of a healthy man of about 45 years of age with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

The normal range in newborns for the first days of life differ from the following table. You must look for the applicable table for newborns.

0.3 mg/dl0.31 mg/dl0.32 mg/dl0.33 mg/dl0.34 mg/dl0.35 mg/dl0.36 mg/dl0.37 mg/dl
0.38 mg/dl0.39 mg/dl0.4 mg/dl0.41 mg/dl0.42 mg/dl0.43 mg/dl0.44 mg/dl0.45 mg/dl
0.46 mg/dl0.47 mg/dl0.48 mg/dl0.49 mg/dl0.5 mg/dl0.51 mg/dl0.52 mg/dl0.53 mg/dl
0.54 mg/dl0.55 mg/dl0.56 mg/dl0.57 mg/dl0.58 mg/dl0.59 mg/dl0.6 mg/dl0.61 mg/dl
0.62 mg/dl0.63 mg/dl0.64 mg/dl0.65 mg/dl0.66 mg/dl0.67 mg/dl0.68 mg/dl0.69 mg/dl
0.7 mg/dl0.71 mg/dl0.72 mg/dl0.73 mg/dl0.74 mg/dl0.75 mg/dl0.76 mg/dl0.77 mg/dl
0.78 mg/dl0.79 mg/dl0.8 mg/dl0.81 mg/dl0.82 mg/dl0.83 mg/dl0.84 mg/dl0.85 mg/dl
0.86 mg/dl0.87 mg/dl0.88 mg/dl0.89 mg/dl0.9 mg/dl0.91 mg/dl0.92 mg/dl0.93 mg/dl
0.94 mg/dl0.95 mg/dl0.96 mg/dl0.97 mg/dl0.98 mg/dl0.99 mg/dl1 mg/dl1.01 mg/dl
1.02 mg/dl1.03 mg/dl1.04 mg/dl1.05 mg/dl1.06 mg/dl1.07 mg/dl1.08 mg/dl1.09 mg/dl
1.1 mg/dl1.11 mg/dl1.12 mg/dl1.13 mg/dl1.14 mg/dl1.15 mg/dl1.16 mg/dl1.17 mg/dl
1.18 mg/dl1.19 mg/dl1.2 mg/dl     
foto de Dr. Javier Muga Bustamante
Written by

Dr. Javier Muga Bustamante

Last update: 27/03/2020


  • Concise Book of Medical Laboratory Technology: Methods and Interpretations. 2nd Edition. 2015. Ramnik Sood. ISBN: 978-93-5152-333-8. Pag. 454.
  • Concise Book of Medical Laboratory Technology: Methods and Interpretations. 2nd Edition. 2015. Ramnik Sood. ISBN: 978-93-5152-333-8. Pag. 454.
  • Thomas L. Bilirubin. In: Thomas L, ed. Clinical laboratory diagnostics. Use and assessment of clinical laboratory results. Frankfurt/Main: TH-Books Verlagsgesellschaft, 1998:192-202.
  • Balistreri WF, Shaw LM. Liver Function. In: Tietz NW, ed. Fundamentals of clinical chemistry. Philadelphia:WB Saunders Company, 1987:733-737. ISBN 9780721656106.
  • Painter PC, Cope JY, Smith JL. Reference information for the clinical laboratory. In: Burtis CA, Ashwood ER, eds. Tietz textbook of clinical chemistry. Philadelphia:WB Saunders Company, 1999;1803pp.
  • Common Terminology Criteria for Adverse Events (CTCAE). Version 5.0.Published: November 27, 2017. U.S. Department of health and human Services. Disponible en:
  • Severity grading in drug induced liver injury. U.S. National Library of Medicine. Disponible en:

Show more

Rating Overview

Share your thoughts about this content

E-mail (Optional):
Add a review