Blood draw
Bilirubin (Indirect/Unconjugated)
Unconjugated bilirubin; hemolysis or liver.
€ 23,00
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Liver and pancreas · Blood
Bilirubin direct (conjugated)
The part of bilirubin that the liver has already processed; raised when the liver or the bile drainage is not working properly.
At a glance
- Measured in blood
- In 1 test panel
- No special preparation
Explanation
Bilirubin direct (conjugated): what is measured?
Bilirubin is the yellow breakdown product of old red blood cells. The liver takes it up and links it to a sugar acid, so that it becomes water-soluble: this is called conjugated or direct bilirubin. This part travels with the bile to the intestine and leaves the body with the stool. Normally there is very little conjugated bilirubin in the blood. The value rises if the liver cells cannot excrete it properly or if drainage through the bile ducts is blocked (cholestasis).
What can it detect?
- Blocked bile drainage (cholestasis), for example due to gallstones or a narrowing of the bile duct
- Liver damage due to viral inflammation (hepatitis), alcohol, medicines or liver cirrhosis
- Distinction from Gilbert's syndrome and from increased breakdown of blood cells, in which it is the unconjugated part that is raised
Result
What does the result mean?
Bilirubin direct (conjugated) too high
A raised conjugated bilirubin indicates that the liver or the bile drainage is not working properly; it does not fit Gilbert's syndrome. Together with a raised alkaline phosphatase and gamma-GT, it fits blocked bile drainage, for example due to gallstones; symptoms are then pain in the upper right abdomen, itching, dark urine and pale stool. Together with a raised ALAT, it fits liver inflammation due to a virus, alcohol or medicines, or advanced liver disease. With a clear rise, the skin and the whites of the eyes turn yellow (jaundice). Rarely: a harmless inherited abnormality in the excretion of bilirubin (Dubin-Johnson or Rotor syndrome), or a tumor that blocks the bile duct.
Bilirubin direct (conjugated) too low
A low or barely measurable conjugated bilirubin is normal and has no significance. There is no condition associated with a conjugated bilirubin that is too low.
After an abnormal result
With a raised conjugated bilirubin, the GP assesses the other liver values, asks about medicines and alcohol and usually has an ultrasound of the liver and bile ducts done. With jaundice, fever or severe pain in the upper right abdomen, further assessment follows quickly and, if needed, referral to a gastroenterologist.
Reliability
How reliable is the test?
Conjugated bilirubin is mainly useful when total bilirubin is raised: it shows whether the cause lies in the liver or the bile ducts, or before them, in the breakdown of red blood cells. If the conjugated part is normal and the other liver values are normal, a slightly raised total bilirubin fits Gilbert's syndrome. A single value says little about the severity or the exact cause; that requires ALAT, alkaline phosphatase, gamma-GT and usually an ultrasound of the liver and bile ducts.
What can affect the result?
- Hemolysis in the tube (red blood cells broken down by a difficult blood draw or finger prick) and exposure of the sample to light disturb the measurement.
- Some medicines and anabolic steroids inhibit bile drainage and raise the value without any liver disease.
- After recovery from jaundice, the value can stay raised for weeks, because part of the processed bilirubin is bound to albumin and disappears slowly.
- Measurement methods differ between laboratories, and at low values the differences are relatively large.
Who it is for
Who is the test useful for?
Useful for
Useful when total bilirubin is raised, to see which part is raised, and with symptoms that fit a problem with the liver or bile drainage: yellow whites of the eyes or yellow skin, dark urine, pale stool, itching or pain in the upper right abdomen. Also useful to check whether a previously found slightly raised bilirubin fits the harmless Gilbert's syndrome. In healthy adults without symptoms, a single test adds little.
How common is it?
A raised conjugated bilirubin in healthy adults without symptoms is unusual. Gallstones are common and usually cause no symptoms; conjugated bilirubin only rises if a stone blocks the bile duct. Viral liver inflammation and liver cirrhosis are much less common in general practice.
NVKC; Thuisarts.nl
Drawbacks and risks
- At low values, measurement methods differ noticeably; without a repeat measurement, a slightly raised result can lead to unnecessary worry and unnecessary testing.
Get tested
Bilirubin direct (conjugated): test panels
Bilirubin direct (conjugated) is part of these test panels. You order online and have your blood drawn at a collection point or collect the sample at home.
Evidence
Sources
This explanation is based on Dutch guidelines and independent information. It is general information, not a diagnosis. Discuss an abnormal result with your GP.
More about risks and resultsMore explanations
Other tests: Liver and pancreas
- ALAT
- Albumin
- Albumin/globulin ratio
- Alkaline phosphatase
- Alpha-1 antitrypsin
- Amylase
- ASAT
- Bilirubin indirect (unconjugated)
- Bilirubin total
- Ceruloplasmin
- Cholinesterase
- Gamma-GT