Liver Blood Tests

  • Liverblood tests are designed to show evidence those abnormalities, for example, inflammation, liver cell damage, has or is occurring within the liver.
  • The blood tests most frequently used for liver disease are the aminotransferase (alanine aminotransferase or ALT and aspartate aminotransferase or AST).
  • Normal levels of ALT ranges from about 7-56 units/liter, and 10-40units/liters for AST.
  • Elevated levels of AST and ALT may signify the level of liver damage in a person.
  • Common causes of elevated ALT and AST are
    • viral liver infections,
    • alcohol abuse,
    • cirrhosis (from any chronic causes),
    • hemochromatosis (iron overload), shock, and/or
    • heart failure.
  • Many drugs may cause elevated AST, and ALT and some medications can cause severe damage (for example, acetaminophen [Tylenol liver damage]).
  • Less common causes of abnormal AST and ALT levels are wide ranging (for example, toxins, and autoimmune diseases)
  • People with mild to moderate elevations of AST and ALT with no or few symptoms should follow-up with their doctor for potential underlying causes of elevated AST and/or ALT.
  • Repeated test levels (monitoring) is useful in some patients (for example, viral-caused and Tylenol-caused elevations) to guide therapeutic treatments.
  • Other liver enzymes, although not measured routinely, may add additional information about liver functions.