Lab Values for Nurses Practice Test 2026 - Free Nursing Exam Practice Questions and Study Guide

An AST to ALT ratio greater than 2:1 is a classic sign of alcohol-related liver disease. This pattern happens because alcohol preferentially damages mitochondria in liver cells, causing a larger release of AST (which is present in both the cytosol and mitochondria) than ALT. Chronic alcohol use also tends to cause vitamin B6 (pyridoxine) deficiency, which lowers ALT activity more than AST, widening the ratio further. By contrast, acute viral hepatitis tends to elevate ALT more than AST, so the ratio is often less than 1. Nonalcoholic fatty liver disease usually shows only mild elevations with ALT and AST being closer in value, giving a ratio around 1. Pancreatitis doesn’t primarily reflect hepatocellular injury, so this specific ratio isn’t a defining feature.