What is a normal bilirubin level?
For adults, normal ends at 21 µmol/L at two NHS labs. A bit high, with your other liver results normal? The most common cause is usually harmless and runs in families.
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What is a normal bilirubin level?
For adults, normal ends at 21 µmol/L at both NHS labs we checked. North Bristol uses below 21, and North West London uses 0 to 21.
It’s usually part of a liver blood test, or done to check for jaundice. Serum just means the liquid part of your blood.
µmol/L means micromoles per litre. It’s how much bilirubin is in each litre of your blood.
- Below 21 µmol/LNormal for adults at two NHS labs.
- 21 up to 40 µmol/LAbove range. Most often Gilbert’s, if other liver results are normal.
- Above 40 µmol/LWell above. If the indirect part alone is above 40, UK guidelines look for rarer causes.
Sources: North Bristol NHS Trust; North West London Pathology; BSG guideline
Ranges can vary from lab to lab. Always read your result against the range printed beside it.
Babies differ. North Bristol uses below 17 for under-1s. North West London reads babies under 14 days against a chart for their age.
Ask your GP what your other liver results showed.
What do total, direct and indirect bilirubin mean?
Bilirubin is a yellow waste made when your body breaks down old red blood cells.
Loose rubbish (indirect bilirubin) travels in your blood to your liver. Your liver bags it up (direct bilirubin) so it can leave your body in bile, a fluid that helps you digest food.
| Line | What it is | Normal for adults |
|---|---|---|
| Total bilirubin | Both kinds added together. Most labs report this one. | Below 21 µmol/L (North Bristol) or 0 to 21 (North West London) |
| Direct (conjugated) | The bagged kind, made by your liver. | 0 to 5 µmol/L at North West London |
| Indirect (unconjugated) | The loose kind, on its way to your liver. | Worked out as total minus direct |
Sources: BSG guideline; North Bristol NHS Trust; North West London Pathology
Which kind is high tells your GP where to look. Too much loose rubbish usually means red cells are breaking down fast, or the liver bags it slowly.
Too many bags in your blood usually means the liver is hurt or the way out is blocked. One NHS lab says a build-up of direct bilirubin is always a sign of a problem.
Only see a total? Ask your GP whether your direct bilirubin was checked. For the other lines, see the liver function test guide.
Why is my bilirubin high if I feel fine?
Most often, it’s Gilbert’s syndrome. It’s the most common cause of a raised bilirubin on its own, and it affects 5 to 8% of people.
It’s inherited. Your liver bags bilirubin more slowly, so a little builds up. The NHS says it does not cause any damage to your liver and does not affect how long you’ll live.
Some people only find out from tests for something else.
What UK liver guidelines advise after a raised bilirubin on its own
- 1
Repeat test
A sample taken after not eating (fasting), with a full blood count and direct and indirect bilirubin.
- 2
Gilbert’s pattern
Total rises further from the indirect part, with no anaemia.
- 3
If anaemic
More tests check whether red cells are breaking down too fast.
- 4
Indirect above 40
Rarer inherited causes are thought about, with a genetic test.
Source: BSG guideline
Anaemia means too few healthy red blood cells. See the full blood count and fasting blood test guides.
Been told you have Gilbert’s? The NHS says to speak to a GP or pharmacist before taking any new medicines. Some, such as statins, may need closer checks.
Never stop or change a prescribed medicine without your prescriber.
What does high bilirubin mean?
It means bilirubin is building up in your blood. Enough of it can cause jaundice, when your skin or the whites of your eyes turn yellow.
| Cause | Examples |
|---|---|
| Red cells breaking down too fast | Haemolytic anaemia (red cells destroyed too early), sickle cell disease (an inherited blood condition). |
| Liver bags it slowly | Gilbert’s syndrome, or rarer inherited causes such as Crigler-Najjar syndrome. |
| Liver disease | Hepatitis (a swollen liver), cirrhosis (scarring of the liver), alcohol-related liver disease. |
| Bile flow blocked or slowed | Gallstones (small stones that can block the tube bile flows through). |
| Other | Pancreatitis (a swollen pancreas), some medicines, certain foods, hard exercise. |
Sources: NHS: jaundice; BSG guideline; North West London Pathology; MedlinePlus
Looking for the level that means jaundice? None of the NHS pages we used gives one. Act on the yellowing, not a number.
Low bilirubin is not usually a cause for concern.
What to do about a high bilirubin
- Read your result against the range printed beside it.
- Ask your GP whether your direct bilirubin and other liver results were checked.
- Ask whether a repeat fasting test with a full blood count would help.
- Tell your GP if you trained hard, slept badly, drank alcohol or drank too little fluid before your test.
- Tell your GP about every medicine you take.
- If yellowing comes and goes, keep a record of when.
Sources: BSG guideline; NHS: Gilbert’s syndrome; MedlinePlus
Never stop or change a prescribed medicine without your prescriber. Hard training moves other results too, so see exercise before a blood test.
Bilirubin levels in newborn babies
Jaundice is common in newborns and usually harmless. A baby’s liver can take a few weeks to work fully.
The yellow is usually most noticeable at about 3 days old. It usually takes about 2 weeks to go.
Staff check the level with a blood test or a light pressed on the skin. NICE says not to judge the level by eye alone, and to read it against the baby’s age in hours.
| Situation | What NICE advises |
|---|---|
| Jaundice in the first 24 hours | Measure bilirubin urgently, within 2 hours. |
| Still yellow after 14 days (born at 37 weeks or later) or 21 days (born earlier) | Measure direct bilirubin. |
| Direct bilirubin above 25 µmol/L | Follow expert advice, as it may mean serious liver disease. |
Source: NICE CG98
Worried about your baby’s colour? Check the urgent signs below.
When to speak to a GP
Gilbert’s may not cause any symptoms, so feeling well tells you little. Get help if:
- Your skin or the whites of your eyes look yellow. Ask for an urgent GP appointment or call NHS 111. You may also have itchy skin, darker pee and paler poo. On brown or black skin, check the whites of your eyes.
- You have Gilbert’s and the yellowing is worse than usual, or doesn’t go within a few days. Ask for an urgent GP appointment or call 111.
- Your bilirubin is above your lab’s range and nobody has told you why. UK guidelines advise thinking about a check for the cause, whatever the level.
- Your baby is over 24 hours old and looks yellow, isn’t getting better, or has dark yellow or brown pee or pale creamy poo. Ask for an urgent GP or midwife appointment, or call 111.
- Your baby has jaundice and is under 24 hours old, sleepier than normal, hard to wake or not feeding. Or they’re floppy, stiff, jerking or twitching, or have no wet nappies. Or they’re 38C or more or 36C or less, feel hot or cold, or shiver. Or they struggle to breathe, grunt, have their tummy sucking in under the ribs, seem breathless or breathe very fast. Call 999 or go to A&E.