Reference ranges
AST reference range
Reference ranges describe the interval a laboratory prints next to your result. They are not a diagnosis of what is “normal” for you personally — your clinician interprets results in context.
General biomarker education — not personalized medical advice. Learn more
What AST measures
AST appears in liver, muscle, and other tissues. A blood value alone does not identify a single cause.
Why ranges differ
Laboratories set their own reference intervals using their methods, equipment, and population data. That is why the range on your Quest report may differ from a LabCorp report — always use the interval printed on your source document.
Common units
AST is often reported in U/L. Confirm units on your original report before comparing values across time.