A 39 on the AST blood test is slightly above the normal range of 10 to 34 international units per liter, notes MedlinePlus. AST, the abbreviation for aspartate aminotransferase, is an enzyme found in the heart, liver and other body tissues.
An elevated AST level usually indicates that there has been some damage to the liver, states MedlinePlus. Causes of a high AST level include hepatitis, cirrhosis, liver cancer, muscle trauma and pancreatitis. In some people, AST levels increase after seizures, burn injuries, cardiac procedures or surgery.
Some laboratories have different normal ranges for the AST test, explains MedlinePlus. Patients concerned with the results of an AST test should speak with a medical professional.