Table 8.

Common liver function tests and their clinical value.

Liver function test	Normal value*	Clinical value
Alanine aminotransferase (ALT)	10–31 U/L	ALT lower than AST in alcoholism
Albumin	3.5–5.2 g/dL	Assess severity/chronicity measures liver protein synthesis
Alkaline phosphatase	25–112 U/L	Diagnose cholestasis and hepatic infiltrations
Aspartate aminotransferase (AST)	10–44 U/L	Early diagnosis and monitoring of hepatic necrosis
Bilirubin (Total)	0.1–1.0 mg/dL	Assess severity of cholestatic liver disease
Gamma glutamyl transpeptidase	16–74 U/L	Diagnose alcohol abuse Marker of cholestasis
Prothrombin time	11.3–16.5 sec	Assess severity of liver disease; measure of liver protein synthesis

^*Normal values vary with the laboratory reporting them (adapted form Larson et al. 2005).