Aspartate Aminotransferase (AST)
Disclaimer: Information on this page is for educational purposes. Consult a physician to interpret your test results. Lissa Health helps track biomarker trends but does not replace medical advice.
What This Test Measures
AST is found in liver, heart, skeletal muscle, and other tissues. It is less liver-specific than ALT.
The AST/ALT ratio helps differentiate alcoholic liver disease (AST>ALT) from viral hepatitis.
Marked AST elevation may indicate myocardial infarction, rhabdomyolysis, or acute hepatitis.
Normal Ranges
| Group | Reference Range |
|---|---|
| Men | 0–37 U/L |
| Women | 0–31 U/L |
| Children | 0–40 U/L |
Reference ranges may vary by laboratory and assay method.
Causes of High Levels
- Alcoholic and viral liver disease
- Myocardial infarction
- Rhabdomyolysis and muscle injury
- Hypothyroidism
- Liver cirrhosis
Causes of Low Levels
- End-stage cirrhosis
- Vitamin B6 deficiency (rare)
Test Preparation
- Fasting 8–12 hours
- Avoid heavy exercise for 48 hours
- Report medications
Related Biomarkers
| Biomarker | Relationship |
|---|---|
| Alanine Aminotransferase (ALT) | AST/ALT ratio |
| Lactate Dehydrogenase (LDH) | General tissue injury |
| Total Bilirubin | Liver function |
FAQ
How often should I take this test?
Annually; with cardiac or liver disease — as directed.
What should I do if my result is abnormal?
Acute elevation with chest pain — seek emergency care immediately.
Last updated: June 2026