Tests and Investigations

A number of tests can be used to diagnose and monitor liver disease. At Children’s Liver Disease Foundation we are always looking into new tests and investigations to help improve and help families.

*This website provides general information but does not replace medical advice. It is important to contact your/your child’s medical team if you have any worries or concerns

Blood tests

Liver function tests (LFTs) are carried out on blood samples in a laboratory.

They are a common way of seeing how well the liver is working. They test the levels of particular proteins and enzymes in the liver as well as the level of bilirubin. Liver function tests are also used to monitor a child’s liver disease over time to see if the liver is getting healthier, getting worse or staying the same. Other blood tests will also need to be done to diagnose the cause of the liver disease.

See below for a chart explaining the different blood tests which are carried out, including the liver function tests, with their expected results.

Urine and Stool

The colour of wee and poo and can provide information about the liver. Pale poo and be a sign of a problem with the liver, along with dark wee. Sending urine samples to the laboratory can give more information for the diagnosis.

Abdominal Ultrasound

This is a scan of the abdomen. It’s the same as the scan that pregnant women have to see their baby and doesn’t hurt at all. The ultrasound can show the size and texture of the liver and other organs such as the gall bladder, bile ducts, spleen and kidneys. It can also show the blood flow into and out of the liver.

Liver biopsy

A liver biopsy may be recommended if tests show that there could be a problem with the liver. The results of the biopsy may indicate if there is a problem with the liver or what it is. A biopsy may not be able to provide a diagnosis but may provide a clue to what other tests may be needed. They can also be used to monitor the condition.

A liver biopsy involves inserting a very thin needle through the tummy and into the liver.

The needle takes a very small sample of the liver. That sample of liver tissue is then sent to the laboratory to be examined under a microscope.Children may either have the procedure done with a local anaesthetic or with general anaesthetic (so they are asleep).

When young people move to adult services they will have the biopsy done whilst they are awake using a local anaesthetic.

Liver function tests explained:

It’s important to note that every child will have their own ‘normal’ and whilst these levels are a guide, it doesn’t necessarily mean a result outside of these ranges is dangerous. Always talk to your child’s medical team if you have any worries about test results. LFTs show the amount of inflammation in the liver, whether the bile ducts are affected and how well the liver is functioning.


Name of test Normal range What does this show?
Bilirubin (SBR)

a) Total bilirubin


b) Conjugated bilirubin



a) 3 – 20 mmol/l

b) Conjugated less than 7 mmol/l

The total bilirubin level corresponds to the level of jaundice present.The amount of conjugated bilirubin compared to the unconjugated bilirubin can show whether jaundice is caused by red blood cells breaking up too quickly (not a liver disease) or is due to a reduced flow of bile out of the liver.

Conjugated means that a sugar has been added to the bilirubin.

Aspartate Aminotransferase (AST) 10 – 40 IU/I High levels can mean there is liver inflammation present.
Alanine Aminotransferase (ALT)
Gamma-Glutamyl Transferase

(GGT, gGT or Gamma GT)

5 – 55 IU/L High levels can mean bile duct inflammation or obstruction.The results can sometimes give information about bile production.
Alkaline Phosphatase (ALP) Less than 350 IU/L High levels can mean there is bile duct inflammation


ALP is not specific to the liver as it is also produced in other organs e.g. bones. Therefore, abnormal levels can be due to processes occurring in other parts of the body.

Total Protein 60 – 80 g/l High and low levels can be used in consideration with the other LFT results
Albumin 35 – 50 g/l Low levels can mean the liver is not making enough, that protein is being lost through the stool or a child is not well nourished.

Another blood test which is helpful to assess how the liver is working is a blood clotting test. Blood is taken, chemicals are added to it in the lab and the time taken for blood to clot is measured.

Name of test Normal range What does this show?
Blood Clotting (Coagulation) Test

a) PT (Prothrombin time)


b) INR (International normalised ratio*)


*INR is a standardised version of the PT for comparison, they both measure the same thing

a) 12 – 15 seconds

b) 0.9 – 1.2

The liver produces substances needed for blood to clot.Raised levels can mean there is less Vitamin K due to a reduced bile flow.

If Vitamin K is given and the result is still raised, it may mean there is damage to the liver.

Other blood tests include:

Name of test What is measured?
Full blood count (FBC) Haemoglobin (Hb)White blood cell count (WBC)

Platelets (Plt) – levels can fall in liver disease if the spleen is enlarged.

Urea and electrolytes Urea and creatinine are waste products removed by the kidneys.Electrolytes include sodium, chloride and calcium.
Blood glucose A high or low level of sugar in the blood can sometimes be a sign of liver damage or a metabolic liver disease.
Ammonia Ammonia is a waste product. It is converted into urea in the liver and is then removed in urine.A higher level than usual may mean there is damage to the liver or an underlying metabolic condition.

Some of these tests may be used to monitor the effects of medications on the body.

This website provides general information but does not replace medical advice. It is important to contact your/your child’s medical team if you have any worries or concerns

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    If you have any questions about this resource, or if you would like information on the evidence used to produce it, please email: info@childliverdisease.org