What are they?

Liver function tests check to see how well your child's liver is working.

The tests may include:

Alkaline phosphatase (ALP).

This test measures the amount of the enzyme ALP in your child's blood.

Total serum protein and albumin.

It measures the amounts of two major groups of proteins in your child's blood (albumin and globulin). It also measures the total amount of protein. An albumin test measures albumin only.

Bilirubin.

It measures the amount of bilirubin in your child's blood.

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

These tests measure the amount of the enzymes ALT and AST in the blood. (Aminotransferase is also known as a transaminase.)

Why are these tests done?

Some liver function tests measure the amount of certain enzymes in the blood. This can help the doctor find out if your child's liver is damaged or inflamed. Other tests measure how well your child's liver can make important proteins or clear waste products from the body.

The doctor will use the test results to help look for certain conditions. These may include hepatitis or gallbladder problems. They may also include liver or bile duct problems that your child was born with.

Test results that are not normal don't always mean that there's a problem with the liver. The doctor can see if there is a problem based on the test results.

These tests also may be done to see how well a treatment for liver disease is working.

How do you prepare for the test?

In general, there's nothing you have to do before this test, unless your doctor tells you to.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm.