Signs and SymptomsIn general, your doctor will ask questions about your symptoms such as what has bothered you, when you noticed it and how severe they have been. If they suspect hepatitis, he or she will ask specifically about flu-like or gastrointestinal symptoms. The doctor will then perform a physical exam and look for signs that might point to the cause of the problem such as an enlarged liver or yellowing of your eyes or skin. After meeting with you, your doctor will probably test some of your blood for any markers of liver dysfunction or inflammation such as the liver enzymes.
Liver EnzymesAn enzyme is a protein that assists in chemical reactions and there are lots of these proteins in the body that do different jobs. The liver uses some of these to help with its essential functions, such as building things up, breaking things down and disposing of various waste products.
Normally the liver keeps tight control of its enzymes, but when the liver is damaged, these enzymes can escape into the blood. Tests can determine if these enzymes are in the blood and tell how much is present. The three most common enzymes doctors use to test for liver damage are alanine aminotransaminase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transaminase (GGT).
It's a good system but there is a big drawback. While liver enzymes can tell if there is liver damage, they can't tell the cause of the damage. If the doctor suspects a viral cause, he or she will order different blood tests that look for specific virus antibodies.