The prevalence of abnormal liver test results in the general population is estimated to be between 10% and 20%. The terms liver tests or liver chemistries are recommended to describe more accurately the tests used to assess liver health, instead of the term liver function tests. Defining normal ranges for liver transaminase levels can be challenging. Levels are affected by factors such as body mass index and sex. Elevated transaminase levels are associated with increased risks of liver-related and all-cause mortality. Patient with signs or symptoms of liver disease or abnormal liver test results should be evaluated to determine the etiology. For patients with abnormal liver test results, the initial evaluation should include a review of previous laboratory test results, medical and family histories, substance use, and drugs, including over-the-counter drugs and herbal supplements. Physical examination results often are normal but findings may be consistent with acute disease. Tests should include a complete blood cell count; alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, and albumin levels; prothrombin time; hepatitis B surface antigen; hepatitis B core antibody; hepatitis C antibody; ferritin and iron levels and transferrin saturation; and right upper quadrant abdominal ultrasonography. Additional tests and imaging should be based on patient-specific risk factors and the pattern of abnormal liver test results.
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