Bilirubin
Total Bilirubin
What this test measures
Bilirubin is a yellow substance made when your body breaks down old red blood cells. Your liver processes bilirubin so it can leave your body. High levels can cause jaundice (yellow skin and eyes).
Understanding the numbers
Typical range: 5-21 µmol/L
Jaundice becomes visible above 50 µmol/L. Slightly raised levels are common and often harmless (Gilbert's syndrome).
- Normal: 0–21 µmol/L
- Mildly raised: 21–50 µmol/L
- Jaundice visible: 50–100 µmol/L
- Markedly raised: 100–200 µmol/L
Key numbers
- 21 µmol/L — Upper limit of normal
- 50 µmol/L — Jaundice becomes visible around here
- 100 µmol/L — Strongly consider urgent investigation
Typical UK laboratory range. Mildly raised bilirubin with normal other liver tests is often Gilbert's syndrome — a harmless genetic variation affecting ~5% of people. Jaundice usually becomes visible above 50 µmol/L. Marked rises need prompt assessment for obstructed bile ducts, acute hepatitis or haemolysis.
Ranges can vary slightly between laboratories — your report may show slightly different numbers. This page does not read or interpret your result; your GP looks at it alongside your history and other tests.
What a higher-than-normal result can mean
- Your liver may not be processing bilirubin properly
- Can cause yellowing of skin or eyes (jaundice)
- May be caused by liver disease or blocked bile ducts
- A harmless condition called Gilbert's syndrome is a common cause of mildly raised levels
When not to wait
Jaundice with certain features needs same-day assessment.
- Jaundice with fever or feeling shivery (possible cholangitis)
- Severe upper tummy pain
- Confusion, drowsiness or change in behaviour
- Vomiting blood or passing black tarry stools
- Rapid worsening over hours to days
- Severe itching that prevents sleep
- Known liver disease with any sudden deterioration
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Questions you could ask your GP
- Could I have Gilbert's syndrome, and does it need any treatment?
- Do I need any further tests to check my liver?
- Should I be concerned about the yellowing of my skin or eyes?
- Are there any foods, drinks, or medicines I should avoid?
Example stories
These are made-up examples to show how results are talked about in real appointments. They are not real patients.
Gilbert's syndrome — mildly raised with fasting
Georgia's bilirubin was 38 µmol/L. Other liver tests and full blood count were normal. She felt well; sometimes her eyes looked slightly yellow when she had a cold or had skipped meals.
What the GP said: “This looks like Gilbert's syndrome — a genetic variant where the liver is slightly slow at processing bilirubin. It's harmless, common, and doesn't need treatment. The number can rise with fasting or illness and settles afterwards.”
Mildly raised bilirubin with otherwise normal liver tests and blood count is most often Gilbert's syndrome. Knowing about it spares future worry whenever the number is a little up.
Jaundice — gallstone in the bile duct
Bhasker was jaundiced, with dark urine and pale stools, and right upper tummy pain. Bilirubin 125, ALP 480, ALT 310. Ultrasound showed a stone in the common bile duct.
What the GP said: “A gallstone is blocking your bile duct — that's why the bilirubin has backed up. I'm referring you urgently to the hospital for an ERCP to remove the stone and for antibiotics.”
What happened next: ERCP removed the stone and a subsequent cholecystectomy prevented recurrence. His bilirubin fell to 20 within two weeks.
Jaundice with dark urine and pale stools, plus upper tummy pain, points to a blocked bile duct. This needs hospital assessment quickly — the risk of cholangitis (a bile-duct infection) is real.
Jaundice — autoimmune hepatitis
Angela had yellow eyes, fatigue and joint pain for three months. Bilirubin 85, ALT 520, smooth muscle antibodies positive.
What the GP said: “This is autoimmune hepatitis — your immune system is attacking your liver. We'll start prednisolone and refer you to hepatology for long-term treatment with immune-suppressing medicines.”
What happened next: Angela's bilirubin and ALT normalised over three months. She was stepped down to azathioprine and stayed in remission.
Jaundice in a younger or middle-aged person, especially a woman, should prompt thought about autoimmune hepatitis. Treatment with immune-modulating medicines is usually effective.
Haemolysis — raised bilirubin from breakdown
Noah had sudden-onset jaundice, dark urine and tiredness. Bilirubin 62, haemoglobin 82, reticulocytes high, Coombs positive.
What the GP said: “Your red blood cells are being broken down faster than normal — autoimmune haemolytic anaemia. The extra bilirubin is from that breakdown. We'll start steroids and refer to haematology.”
What happened next: Noah responded to steroids; his haemoglobin rose and bilirubin fell over six weeks.
Bilirubin can also rise from outside the liver — when red cells are being destroyed faster than the liver can cope. The haemoglobin, reticulocyte count and blood film tell you if that's what's happening.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.