AST

Understanding the marker

AST is found in liver, heart, and muscle. It often tracks ALT but is less specific to the liver.

AST can arise from liver or muscle and is less liver-specific than ALT. Recent strenuous exercise can raise it. The AST/ALT pattern can support a clinical assessment but cannot on its own identify alcohol exposure or diagnose a specific liver disease.

What does high AST mean?

AST is found in muscle as well as liver cells. A high result is read with ALT, other relevant tests, symptoms and recent physical activity. The value alone does not show the source or cause.

What does low AST mean?

An isolated low AST is usually of limited significance. The other liver tests and any symptoms remain part of the assessment.