Hepatitis

• Alanine aminotransferase (ALT)  an enzyme mainly found in the liver; the best test for detecting hepatitis
• Alkaline phosphatase (ALP)  an enzyme related to the bile ducts; often increased when they are blocked
• Aspartate aminotransferase (AST)  an enzyme found in the liver and a few other places, particularly the heart and other muscles in the body
• Bilirubin  two different tests of bilirubin often used together (especially if a person has jaundice): total bilirubin measures all the bilirubin in the blood; direct bilirubin measures a form made in the liver 
• Albumin  measures the main protein made by the liver and tells how well the liver is making this protein
• Total Protein - measures albumin and all other proteins in blood, including antibodies made to help fight off infections

These and other tests may be included in the liver panel. Other tests that could be requested as part of the panel are gamma-glutamyl transferase (GGT), lactic acid dehydrogenase (LDH), and prothrombin time.

When are these tests ordered?
One or more of these tests are ordered when symptoms suspicious of a liver condition are noticed. These include: jaundice, dark urine, or light-colored bowel movements; nausea, vomiting and/or diarrhea; loss of appetite; vomiting of blood; bloody or black bowel movements; swelling or pain in the belly; unusual weight change; or fatigue or loss of stamina. One or more of these tests may also be ordered when a person has been or may have been exposed to a hepatitis virus; has a family history of liver disease; has excessive alcohol intake; or is taking a drug that can cause liver damage.