Understanding your AST blood test
An AST test measures aspartate aminotransferase (AST), an enzyme found in the liver as well as muscles, the heart, and other tissues. When cells are irritated or injured, AST may enter the bloodstream. For this reason, AST is one helpful clue clinicians use when evaluating possible liver inflammation or injury.
If AST appeared on your routine lab results or you were told your liver enzymes are elevated, remember that one number cannot diagnose liver disease. AST is usually considered with ALT, bilirubin, alkaline phosphatase, your symptoms, health history, medications, alcohol use, recent exercise, and sometimes additional testing. The Liver Hope Foundation provides educational support to help you prepare for informed conversations with your healthcare professional.
High AST is a signal to follow up, not a diagnosis or a reason to panic. Levels can rise with liver inflammation, alcohol use, certain medications, intense exercise, or muscle injury. Review your complete lab panel with a qualified healthcare professional, who can determine whether repeat testing, additional evaluation, or monitoring is appropriate. Do not stop prescribed medication or self-treat based on one result.
Seek prompt medical care for yellowing of the skin or eyes, confusion, severe abdominal pain, vomiting blood, or black stools. The answers below can help you understand common AST questions and prepare for your appointment.
Frequently asked questions about AST
Take the next informed step
Schedule a conversation with a healthcare professional to review your complete lab results and discuss what follow-up may be right for you. The Liver Hope Foundation does not order or sell AST tests, but our liver-test and lab-results resources can help you prepare questions for your visit.