Causes of elevated aspartate aminotransferase, or AST, levels include a heart attack; liver, kidney or lung damage; medicines; high doses of vitamin A; and mononucleosis, states WebMD. Normal levels for adult women and men range between 10 and 36 units per liter and 14 and 20 units per liter respectively.
Aspartate aminotransferase is an enzyme present in the heart, liver, pancreas, red blood cells and muscle tissue with small amounts in the bloodstream, explains WebMD. An increase of AST in the blood usually indicates damage to an organ, and the higher the level of AST in the blood, the greater the damage to the affected organ. The enzyme's former name was serum glutamic oxaloacetic transaminase, or SGOT.
An AST test helps doctors check for liver damage, identify liver disorders such as cirrhosis, determine the cause of jaundice, and monitor and check on the effectiveness of a particular treatment, adds WebMD. In addition, it helps doctors keep track of the effects of medicines that are harmful to the liver. Doctors usually test for AST at the same time as they test for another enzyme, alanine aminotransferase, or ALT. Test results that show elevated levels of both the AST and the ALT strongly indicate liver damage or damage to another organ.