| Mildly elevated ALT level (less than 1.5 times normal) | ALT value could be normal for gender, ethnicity or body mass index. |
| Consider muscle injury or myopathy. |
| Alcoholic hepatitis | Laboratory values can appear cholestatic, and symptoms can mimic cholecystitis. |
| Minimal elevations of AST and ALT often occur. |
| AST level greater than 500 U per L | The AST elevation is unlikely to result from alcohol intake alone. |
| In a heavy drinker, consider acetaminophen toxicity. |
| Common bile duct stone | Condition can simulate acute hepatitis |
| AST and ALT become elevated immediately, but elevation of AP and GGT is delayed. |
| Isolated elevation of GGT level | This situation may be induced by alcohol and aromatic medications, usually with no actual liver disease. |
| Isolated elevation of AP level (asymptomatic patient with normal GGT level) | Consider bone growth or injury, or primary biliary cirrhosis. |
| AP level rises in late pregnancy. |
| Isolated elevation of unconjugated bilirubin level | Consider Gilbert syndrome or hemolysis. |
| Low albumin level | Low albumin is most often caused by acute or chronic inflammation, urinary loss, severe malnutrition or liver disease; it is sometimes caused by gastrointestinal loss (e.g., colitis or some uncommon small bowel disease). |
| Normal values are lower in pregnancy. |
| Blood ammonia level | Blood ammonia values are not necessarily elevated in patients with hepatic encephalopathy. |
| Determination of blood ammonia levels is most useful in patients with altered mental status of new onset or unknown origin. |