What is a liver functioning test and why is it done?

Last updated Aug 25, 2021

Different parts of the human body function in a unique manner. Hence specific parts and organs need individualized and specific tests. One such test is the liver functioning test that is used to determine the overall functioning of the liver.

Understanding the liver function test:

Liver function test is also called liver chemistries or simply an LFT test. By measuring the number of proteins, bilirubin, and liver enzymes in the blood, the liver function test can reflect the health of the liver. Highlighted below are a few conditions in which an LFT test is conducted:

To check if some medicines known for impacting the liver are causing it harm.
To assess the damage from infections in the liver like hepatitis B and hepatitis C.
In case a patient already has a liver disease, a liver function test can help determine the extent of the disease and treatment on the liver.
In case a patient shows symptoms that can be because of a liver disorder.
If one drinks a lot of alcohol
In case a patient had gallbladder disease
In case of medical conditions like high blood pressure, high triglycerides, anemia, diabetes, etc.

In a liver function test, there are several different types of tests, and each test monitors and assesses different parts and functions of the liver. Listed below are the tests used to examine any abnormalities with the liver.

Albumin:

Alumni is an important protein that exists in the liver, and it performs essential functions like nourishment of tissue, transportation of vitamins, hormones, and other substances throughout the body as well as preventing fluid from leaking out of blood vessels.

An albumin liver functioning test, therefore, verifies how well the liver is producing this protein and a low count can be indicative of inflammation, kidney disease, or infection.

Bilirubin:

Ordinarily, the liver processes a compound known as bilirubin which is a waste product generated when red blood cells break down. Bilirubin is processed by the liver before it is excreted out of the body in the form of stools.

A bilirubin LFT test checks if the level of bilirubin is normal in the liver. An unusually high content can indicate that the liver is not functioning properly.

Alanine transaminase also abbreviated to ALT:

Alanine transaminase is used by the liver in the process of protein metabolization. An improper liver can cause ALT to be released into the blood thus causing the overall body’s ALT level to rise. An ALT liver functioning test can help monitor if normal levels of this compound exist, thus checking the functioning of the liver in the process.

Aspartate aminotransferase also abbreviated to AST:

Unlike ALT, Aspartate aminotransferase is an enzyme that is not found exclusively in the liver. It is also prevalent in muscles, heart, and liver and so an AST test does not necessarily indicate a problem with the liver. An AST liver functioning test is coupled with an ALT test so that the scope of the examination can be narrowed to the liver.

Alkaline phosphatase also abbreviated to ALP:

Alkaline phosphatase is present in the liver, bile ducts as well as bones and it is an enzyme. ALP liver test is also not recommended in isolation, and it is usually coupled with other liver function tests.

Preparation:

A doctor usually hands out a list of instructions to follow before one gets a liver function test. This is for the part of the test that involves the collection of the blood sample. Certain types of food, medications, and substances are known to impact the level of proteins and enzymes in the blood and hence the doctor may ask you to steer clear of them. One should remember to keep one hydrated before the liver functioning test.

How is the test performed?

An LFT test usually involves the collection of a blood sample, so the procedure is routine. A healthcare worker usually cleans one’s arm to decrease the chances of infection. Then they wrap an elastic band on the upper arm so that veins can be seen more visibly. Finally, a needle is used to inject the skin and draw out the blood sample which is sent to the lab for further testing. The healthcare worker will then press the site of injection with a cotton swab or a bandage, thus concluding the process.

Conclusion

A liver functioning test is very important as the liver performs many essential functions for the human body. The test is further divided into different tests to check specific components in the working of the liver. The reasons for the test, its procedure, and how to prepare for it have all been presented above and can help anyone trying to gain basic information about a liver functioning test.