Some liver function tests check the levels of certain enzymes that are essential to chemical reactions that help the liver function normally. These tests include:
- Alanine aminotransferase (ALT) and aspartate aminotransferase (AST). These enzymes are involved in processing proteins. Too high levels of ALT and/or AST can signal that the liver is injured or damaged.
- Alkaline phosphatase (ALP). ALP levels that are higher than normal can be a sign of liver diseases,blocked bile ducts, or other conditions.
- Gamma-glutamyl transpeptidase (GGT) is an enzyme found in large amounts in your liver, bile ducts and pancreas. High levels of GGT in the blood may signal liver or bile duct damage.
- Bilirubin tests. Bilirubin is a byproduct of the normal breakdown of red blood cells. If your liver is damaged, bilirubin can leak out of your liver into your blood, causing your skin and eyes to appear yellow (jaundice).
- Globulin and albumin are proteins made in the liver. Low levels of these proteins may indicate liver damage.
- An alpha-1 antitrypsin test measures the amount of a protein that helps protect the liver (and the lungs) from damage. A deficiency in alpha-1 antitrypsin may signal a rare form of cirrhosis. An alpha-1 antitrypsin deficiency can be inherited.
- Prothrombin time (PT) test. Prothrombin is a protein made in your liver that helps with normal blood clotting. A prothrombin time test measures how long it takes for the liquid portion of your blood (plasma) to clot. A high prothrombin time can be a sign of liver damage.