Liver function tests
Liver function tests may be arranged to help diagnose or monitor liver problems. These blood tests may also be called LFTs, liver panel or hepatic function tests.
The liver's job is to filter blood as it travels around the body, but it can become damaged or affected by disease.
Why are liver function tests needed?
A doctor may arrange liver function tests as part of a range of health check blood tests or as standalone tests to:
- Check the health of the liver and that it is working normally
- Diagnose liver-related conditions after symptoms such as jaundice, urine problems, poo colour changes or gallstones
- Monitor or diagnose liver conditions, including hepatitis
- Monitor the liver's health if taking certain medications
- Check for liver damage from alcohol abuse
- Check the health of a transplanted liver.
No special preparation is needed before having a liver function test, such as fasting. A small tube of blood is taken from a vein in the arm and sent for laboratory testing. The results will usually be made available a few days later through the doctor who arranged the test.
Liver function tests include:
Alanine transaminase (ALT) and aspartate aminotransferase (AST): Higher readings may suggest inflammation of liver cells or the death of some cells due to liver damage.
Alkaline phosphatase (ALP): Higher readings suggest liver disease or bile duct blockages.
Albumin: If levels are low, this suggests a lot of lost liver tissue.
Total protein: This reading is important for checking conditions like hepatitis.
Total bilirubin, conjugated bilirubin: Presence of bilirubin suggests liver disease or problems with bile or gallstones, or conditions affecting red blood cells.
The results of each test are looked at together to help check the overall workings of the liver, with values for different tests taken alongside each other for diagnosis and monitoring of conditions.
Depending on the results, a doctor may arrange further tests - or repeat the tests at a later date.