Liver function can be measured by looking at blood levels of the liver enzymes AST, ALT, ALP and GGT or levels of other substances produced by the liver.

High levels of liver enzymes may indicate, among other things: viral hepatitis or other viral infections, the presence of a tumour, alcoholism or diabetes.

You may have to fast (not eat or drink) before some of these tests; check with your doctor or the laboratory first.