AST (SGOT)
Aspartate aminotransferase (AST), also called SGOT, is an enzyme found in the liver, heart, skeletal muscle, kidneys, and brain. When these tissues are damaged, AST leaks into the bloodstream. While AST is part of liver function tests, it is less liver-specific than ALT. The AST/ALT ratio helps distinguish different causes of liver disease.
Reference Ranges
Male
10 – 40
U/L
Female
9 – 32
U/L
Child
10 – 40
U/L
Ages 1–18
Reference ranges may vary by laboratory. Always compare with the range printed on your lab report.
What Low Levels Mean
Low AST is normal and has no clinical significance.
What High Levels Mean
AST elevation mirrors ALT in liver diseases but also rises in heart attacks (myocardial infarction), muscle injury (rhabdomyolysis), and hemolysis. The AST/ALT ratio above 2:1 suggests alcoholic liver disease. Very high AST (>1000 U/L) indicates acute hepatitis, drug toxicity, or ischemic liver injury.
Frequently Asked Questions
What does an AST/ALT ratio above 2 mean?
An AST/ALT ratio greater than 2:1 is characteristic of alcoholic liver disease. In most other liver diseases (viral hepatitis, fatty liver), ALT is higher than AST. This ratio helps doctors differentiate the cause of liver enzyme elevation.
Can a heart attack raise AST?
Yes. AST rises within 6–12 hours of a heart attack and peaks at 24–48 hours. However, troponin has largely replaced AST for diagnosing heart attacks because it is far more specific to heart muscle.
Should I stop alcohol if AST is elevated?
If alcohol is contributing to AST elevation, stopping or reducing intake is strongly recommended. The liver can regenerate — AST levels often normalize within weeks to months of abstinence. Continued drinking can lead to alcoholic hepatitis and eventually cirrhosis.
This information is for educational purposes only and should not replace professional medical advice. Always consult your doctor for interpretation of your test results.
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