Definition
There are a number of different tests for liver function. Each has its own name, as listed in the section below.
Who is a candidate for the test?
Liver function tests are ordered to see if the person's liver is healthy and functioning properly.
How is the test performed?
Blood for the test is usually taken from a person's forearm. First, a tight band is put on the upper arm to make the veins swell below it. An area of skin on the forearm over the vein chosen is cleansed.
A needle is inserted into the vein and a sample of blood is collected in a tube.
The laboratory then measures the amount of the appropriate marker in the blood:
albumin, a protein synthesized by the liver
ALP, an enzyme found in the liver, bones and placenta
ALT (SGPT), an enzyme found primarily in liver cells
AST (SGOT), an enzyme found in the liver as well as many other body organs
serum bilirubin, a waste product formed by the breakdown of red blood cells
urine bilirubin
GGT, an enzyme present in the liver, pancreas and kidney
LDH, an enzyme found in the liver and many other body cells
PT or prothrombin time, which tests the blood's ability to clot
total cholesterol, a substance stored in the liver
total protein, a nutrient normally broken down by the liver and its enzymes
What is involved in preparation for the test?
Specific instructions should be requested from the healthcare professional.
What do the test results mean?
The significance of each test is described in the article specific to that test.
Author: David T. Moran, MD Date Written: 01/06/00 Medical Review: Jeff Fenyves, MD Date Written: 10/9/2006 Reviewer: Reginald Finger, MD Date Reviewed: 11/1/2006
Contributors
Potential conflict of interest information for reviewers available on request
