Liver Function Testing

Liver function tests are blood tests that may be performed as part of a patient’s routine lab work, to gauge the progression of a person’s liver disease, or to determine whether a condition or medication may be damaging a patient’s liver. Commonly referred to as liver enzyme tests, liver test panels evaluate the levels of AST and ALT liver enzymes (aspartate aminotransferase and alanine aminotransferase) in the blood to determine if liver damage has occurred. Several other liver enzymes are also tested to determine whether bile is flowing normally or may possibly be slowed by a blockage. True liver function tests also evaluate blood clotting factors in an evaluation called prothrombin time (PT) and provide an international normalized ratio (INR) for reporting this valuation. Elevated PT and INR numbers may indicate advanced liver disease.