AST: Definition, Uses, and Clinical Overview
Aspartate aminotransferase (AST) is a blood test commonly used in liver and gastrointestinal (GI) medicine. AST is an enzyme found inside liver cells and several other tissues, including muscle. When cells are injured, AST can leak into the bloodstream and become measurable. Clinicians most often interpret AST alongside other “liver enzymes” and liver function tests.