What is a liver function test?
Liver function tests help diagnose and monitor liver disease through blood tests. The tests measure the level of certain proteins and enzymes in the blood. Certain enzymes are released by the liver when it is damaged or diseased, so it is useful to measure them to serve as an indicator of the liver’s condition. The same can be said for the measurement of proteins, such as bilirubin, which is a waste substance in the blood that is normally removed by a properly functioning liver.
What does a liver function test consist of?
If your doctors recommend a liver function test, it is very likely that a series of tests will be performed to measure different enzymes and proteins. During a liver function test, a blood sample is taken through a small needle in a tube. The needle usually draws blood from under the bend of your arm. Once the blood samples are obtained, they are sent to a laboratory for testing, which may take a few hours or days, depending on whether or not the laboratory is on site.
Liver function tests are performed to diagnose liver disease and its progression.
What is a liver function test for?
Generally, a liver function test is used to:
- Determine the severity of a disease, such as cirrhosis (scarring of the liver).
- Detect liver infections (hepatitis, for example).
- Measure the progression of liver disease, such as hepatitis, and see how successful the treatment is.
- Check that the drugs do not produce side effects.
If the following symptoms are present, a liver function test will be performed to help determine a diagnosis:
- Yellow eyes or skin (jaundice).
- Tiredness
- Nausea
- Poor appetite
- Dark urine and light stools
How can you prepare for a liver function test?
Before performing a liver function test, eating and drinking should be avoided for a certain period of time, as they may affect the results. Some medications should also be avoided before performing a liver function test.
What would a “bad” result mean?
Normal results may differ among men, women and children. When you receive your results, your numbers will be shown next to the normal and healthy range. If your results are not normal, further testing will be done to help get a diagnosis or treatment plan. Finally, your specialist will explain the results obtained and what the next steps will be.