What Liver Function Tests Are Included in Pre-Employment Physical Exams?

When undergoing pre-employment health screening, liver function testing typically includes a standardized panel of blood-based biochemical assays designed to assess hepatocyte integrity, synthetic capacity, and biliary excretion. The core components routinely measured are serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bilirubin, direct (conjugated) bilirubin, albumin, and total protein. ALT and AST reflect hepatocellular injury—elevations suggest inflammation or necrosis, with ALT being more liver-specific than AST. ALP and GGT serve as markers of cholestasis; disproportionate increases may indicate biliary obstruction or drug-induced injury. Bilirubin fractions help differentiate between hepatocellular dysfunction and impaired bile flow, while albumin and total protein evaluate the liver’s synthetic function—low albumin levels may signal chronic liver disease or malnutrition. Although not universally included in all pre-employment panels, some employers also request prothrombin time (PT) or international normalized ratio (INR) to further assess coagulation factor synthesis. Interpretation requires clinical correlation: isolated mild enzyme elevations may be transient and benign, whereas persistent abnormalities warrant further evaluation—including viral hepatitis serology, imaging, or specialist referral.