Lab test glossary · Liver
AST: what it means
Also known as: aspartate aminotransferase, SGOT
AST is an enzyme found in the liver and muscle; raised levels can reflect liver or muscle injury, and it's interpreted alongside ALT.
What it measures
AST (aspartate aminotransferase) is found in the liver but also in muscle and other tissues, so it's slightly less liver-specific than ALT. The ratio of AST to ALT can give clinicians a hint about the underlying cause.
Typical range
Often roughly 8–48 U/L, varying by lab.
Reference ranges differ between labs and are printed on your own report — always read your result against that range, not a general one.
What a high result can mean
- Liver inflammation from fatty liver, alcohol, medications, or hepatitis
- Muscle injury or strenuous exercise
- Less commonly, heart-muscle injury
A high value is a starting point for a conversation, not a diagnosis — many causes are benign or temporary.
Why the trend matters
Because AST comes from several tissues, its pattern over time — and its relationship to ALT — is more informative than a single value.
When to talk to your doctor
Discuss persistent AST elevations with your doctor, particularly alongside ALT.
This page is general education about a common lab test — it isn’t medical advice and can’t interpret your specific result. What a value means depends on your history, symptoms, and the rest of your labs, which is a conversation for you and your clinician.