Is my AST (Aspartate Aminotransferase) normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal AST level?
AST is a liver enzyme also found in the heart, muscles, and kidneys. Elevated AST can indicate liver damage, but also muscle injury or strenuous exercise. It's most useful when compared with ALT — an AST/ALT ratio helps distinguish liver causes from other sources.
| Range | Values |
|---|---|
| Standard Reference | 10–35 U/L |
| Optimal | 10–30 U/L |
| High Risk | > 50 U/L |
What causes abnormal AST levels?
Elevated AST can be caused by liver conditions (hepatitis, fatty liver, cirrhosis), heavy alcohol use, muscle damage from intense exercise, heart damage (AST is also found in cardiac tissue), certain medications (statins, NSAIDs, acetaminophen), and celiac disease. Unlike ALT, AST is not specific to the liver.
When should you see a doctor?
See your doctor if AST is above 50 U/L on two consecutive tests (not after heavy exercise), if both AST and ALT are elevated, if you have symptoms like jaundice, abdominal pain, or dark urine, or if you regularly consume more than 2 alcoholic drinks per day.
Where to get a AST test
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Related biomarkers
These biomarkers are often tested alongside AST for a more complete picture.
Frequently asked questions
What is a normal AST level?
Can exercise raise AST?
What is the AST/ALT ratio?
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Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.