Aspartate aminotransferase (AST)

Aspartate aminotransferase (AST) is an enzyme found mostly in the liver, heart, muscles, and other tissues. It plays a key role in converting amino acids into energy. When these tissues are damaged or inflamed—such as in liver disease, heart problems, or muscle injury—(AST leaks into the bloodstream. A blood test measuring AST levels helps doctors assess tissue health and identify possible liver or heart issues. Elevated AST levels may indicate injury or disease, but they are usually considered alongside other tests for a comprehensive diagnosis.