ALP (alkaline phosphatase) helps to break down proteins in your body. Abnormal levels of ALP in your blood can suggest a problem with your liver or gallblader.
AST (aspartate aminotransferase) is an enzyme made by your liver. Normally your AST levels will be low. But when your liver is damaged, it releases more AST into your blood, causing levels to rise.
ALT (alanine aminotransferase) is another enzyme produced by your liver. Like AST, your ALT levels should usually be low. But your liver damage causes higher levels to be released into your bloodstream.
Gamma-glutamyl transpeptidase (GGT) is another liver enzyme. When your liver is injured or there is an obstruction to your flow of bile, the GGT concentration in your bloodstream increases.
Bilirubin is a yellow substance made from the normal breakdown of red blood cells. Since your liver helps remove bilirubin from your body, abnormal levels can indicate your liver is not functioning properly.