AST
An enzyme found in liver, muscle and heart cells that rises with injury to these tissues.
| Typical reference range (male) | 10–40 U/L |
| Typical reference range (female) | 9–32 U/L |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Aspartate aminotransferase participates in amino acid metabolism and is present in the liver, skeletal muscle, heart, kidneys and red blood cells. It is released into the blood when these cells are damaged.
Why it matters
AST is used with ALT to assess liver injury. Because it is less liver-specific, an isolated AST rise often points to muscle. The AST/ALT ratio helps distinguish causes, and AST is used in fibrosis scores such as FIB-4.
What a high result can mean
Causes include fatty liver, alcohol-related liver disease (often AST greater than twice ALT), hepatitis, cirrhosis, medications, recent intense exercise or muscle injury, hemolysis and hypothyroidism.
What a low result can mean
Low AST is generally not significant; it can reflect vitamin B6 deficiency.
What affects the result
Strenuous exercise can raise AST for several days; hemolysis of the sample falsely elevates it. Check CK if muscle is the suspected source. Alcohol reduction and weight loss lower liver-derived AST.
Units and conversion
Usually reported in U/L.
- From IU/L: multiply by 1 to get U/L
- From ukat/L: multiply by 60 to get U/L
Also called on lab reports
AST (SGOT), SGOT, Aspartate Aminotransferase, Aspartate Transaminase, AST/SGOT, Aspartate Aminotransferase (AST)
Related tests: Liver
This page is educational and does not replace advice from a healthcare professional.