Bilirubin Test Normal Range: A Complete Guide
Bilirubin test helps assess liver health by measuring total, direct, and indirect bilirubin levels. Learn the normal ranges for adults, children, and newborns, causes of high bilirubin, symptoms, and what abnormal results may mean for your health.
Written by Dr. Mohammed Kamran
Reviewed by Dr. D Bhanu Prakash MBBS, AFIH, Advanced certificate in critical care medicine, Fellowship in critical care medicine
Last updated on 5th Sep, 2025
When your doctor orders a liver function panel, one of the key numbers they look at is your bilirubin level. But what does it mean if your result is high, low, or within the bilirubin test normal range? This yellow pigment, a byproduct of the normal breakdown of red blood cells, is a crucial indicator of your liver's health and the efficient function of your biliary system. Understanding your bilirubin levels can feel confusing, but it doesn't have to be. This guide will demystify the bilirubin test, breaking down the normal ranges for adults, newborns, and children. We'll explore what causes abnormal levels, the symptoms to watch for, and what steps you can take next if your results are outside the standard range. Whether you're reviewing your own lab report or preparing for a test, this article will provide the clear, actionable information you need.
What is Bilirubin and Why is it Tested?
Bilirubin is an orange-yellow substance found in bile, a fluid your liver produces to help digest fats. It’s created when your body breaks down old or damaged red blood cells. This process is entirely normal and happens continuously. The liver's job is to filter this bilirubin from the blood, process it, and excrete it into the bile, which eventually leaves the body through stool, giving it its characteristic brown colour.
A bilirubin test is ordered to:
• Check liver function: It's a key part of a standard liver panel.
• Investigate jaundice: The yellowing of the skin and eyes is a direct result of high bilirubin levels.
• Diagnose conditions: Such as hepatitis, cirrhosis, gallstones, or hemolytic anaemia.
• Monitor treatment: To see if a treatment for liver disease is working.
• Evaluate newborns: For jaundice, which is very common but must be managed to prevent complications.
Breaking Down the Bilirubin Test Normal Range
The bilirubin test doesn't just give one number. It typically reports three values, and understanding the difference is critical to interpreting your results.
Total Bilirubin
This is the sum of both the direct and indirect bilirubin in your blood.
Normal Range: 0.1 to 1.2 mg/dL (milligrams per deciliter). Some labs may extend the upper limit to 1.3 or 1.4 mg/dL. It's always essential to refer to the specific reference range provided by your laboratory.
Direct Bilirubin (Conjugated Bilirubin)
This is the bilirubin that has been processed by the liver and is attached to a sugar (glucuronic acid), making it water-soluble so it can be excreted.
• Normal Range: 0.0 to 0.3 mg/dL. An elevated direct bilirubin level typically points to a problem with the liver's ability to excrete bile or a blockage in the bile ducts.Consult a Specialist for Personalised Advice
Indirect Bilirubin (Unconjugated Bilirubin)
This is the bilirubin that has not yet been processed by the liver. It is fat-soluble and travels through the bloodstream bound to albumin.
• Normal Range: It is usually calculated by subtracting the direct bilirubin from the total bilirubin. It typically makes up the majority of the total bilirubin in a healthy person.
Understanding the ratio of direct to indirect bilirubin helps doctors pinpoint the cause of the problem. For instance, a high indirect level suggests increased red blood cell breakdown, while a high direct level suggests a liver or drainage issue.
Normal Bilirubin Levels in Newborns and Children
Newborns have significantly higher bilirubin levels than adults. This is because they have a higher red blood cell count at birth, and their immature livers are not yet efficient at processing and excreting bilirubin. This leads to physiological jaundice, which appears on the 2nd or 3rd day of life and usually resolves on its own within two weeks.
• Full-Term Newborn Normal Range: Levels can peak as high as 10-12 mg/dL around the 3rd to 5th day of life and are often not treated unless they exceed certain thresholds based on the baby's age in hours.
• Preterm Newborn Normal Range: Preterm babies have even less mature livers and may have higher peak levels, often monitored more closely.
Doctors use special nomograms to decide if treatment (like phototherapy) is needed. For older children, the normal range aligns closely with that of adults.
What Does a High Bilirubin Level Mean?
A high bilirubin level, known as hyperbilirubinemia, is the primary cause of jaundice. The cause depends on which type of bilirubin is elevated.
Causes of High Indirect (Unconjugated) Bilirubin
This often indicates a problem before the liver has processed the bilirubin.
• Gilbert's Syndrome: A common, harmless genetic condition where the liver has a reduced ability to process bilirubin, causing mild, fluctuating elevations, often during illness or fasting.
• Hemolytic Anaemia: Conditions where red blood cells are destroyed faster than the liver can process the bilirubin (e.g., sickle cell anaemia, malaria, autoimmune disorders).
• Newborn Jaundice: As discussed above.
Reaction to Blood Transfusions.
Causes of High Direct (Conjugated) Bilirubin
This points to a problem after the liver has processed the bilirubin, preventing its excretion.
• Bile Duct Obstruction: Blockages caused by gallstones, tumours, or inflammation.
• Hepatitis: Inflammation of the liver (viral, alcoholic, autoimmune) that damages liver cells and disrupts bile flow.
• Cirrhosis: Scarring of the liver from long-term damage.
• Medications: Certain drugs can cause drug-induced liver injury that impairs bile excretion.
Symptoms of High Bilirubin: Beyond Yellow Skin
The most well-known symptom is jaundice—a yellow tint to the skin, the whites of the eyes (scleral icterus), and mucous membranes. However, other symptoms often accompany high bilirubin levels, depending on the underlying cause:
• Dark-colored urine (often described as tea-colored)
• Pale, clay-colored stools
• Fatigue and weakness
• Abdominal pain and swelling
• Nausea and vomiting
• Itchy skin (pruritus)
What to Do If Your Bilirubin Level is Abnormal
First, don't panic. A slightly abnormal result doesn't always indicate a serious problem. The most important step is to discuss the results with your doctor. They will interpret your bilirubin level in the context of:
• Your other liver enzyme tests (ALT, AST, ALP)
• Your complete medical history and symptoms
• A physical examination
They may order follow-up tests, such as an ultrasound of your liver and gallbladder, more specific blood tests, or other imaging studies to determine the root cause.
Conclusion: Understanding Your Health
Knowing the bilirubin test normal range empowers you to be an active participant in your healthcare. While this guide provides a comprehensive overview, it is not a substitute for professional medical advice. Your bilirubin level is a powerful clue, but it's just one piece of the puzzle. An abnormal result, whether high or low, is a signal to work with your doctor to investigate further. Many causes, like Gilbert's syndrome, are completely benign and require no treatment. Others may need prompt medical attention. By understanding what this test measures and what the numbers mean, you can ask informed questions and better understand your doctor's recommendations for maintaining your liver health and overall well-being.
Consult a Specialist for Personalised Advice
Consult a Specialist for Personalised Advice
Dr. Praveen Kumar Mukka
General Physician/ Internal Medicine Specialist
21 Years • MBBS, MD General Medicine
Hyderabad
Apollo 24|7 Clinic - Telangana, Hyderabad
(25+ Patients)
Dr. D Bhanu Prakash
General Practitioner
10 Years • MBBS, AFIH, Advanced certificate in critical care medicine, Fellowship in critical care medicine
Hyderabad
Apollo 24|7 Clinic, Hyderabad
Dr. Shubham Chauhan
General Practitioner
4 Years • MBBS
Lucknow
Apollo 24|7 Clinic - Uttar Pradesh, Lucknow
Dr. Sahana B
General Practitioner
3 Years • MBBS
Koppal
Khushi multi-speciality hospital, Koppal
Dr. Gaddam Manoj
General Practitioner
1 Years • MBBS
Hyderabad
Aaradhya clinic, Hyderabad
Consult a Specialist for Personalised Advice
Dr. Praveen Kumar Mukka
General Physician/ Internal Medicine Specialist
21 Years • MBBS, MD General Medicine
Hyderabad
Apollo 24|7 Clinic - Telangana, Hyderabad
(25+ Patients)
Dr. D Bhanu Prakash
General Practitioner
10 Years • MBBS, AFIH, Advanced certificate in critical care medicine, Fellowship in critical care medicine
Hyderabad
Apollo 24|7 Clinic, Hyderabad
Dr. Shubham Chauhan
General Practitioner
4 Years • MBBS
Lucknow
Apollo 24|7 Clinic - Uttar Pradesh, Lucknow
Dr. Sahana B
General Practitioner
3 Years • MBBS
Koppal
Khushi multi-speciality hospital, Koppal
Dr. Gaddam Manoj
General Practitioner
1 Years • MBBS
Hyderabad
Aaradhya clinic, Hyderabad
