What Is AST in a Blood Test?

AST stands for Aspartate Aminotransferase (SGOT). Found in liver, heart, skeletal muscle, kidneys, and brain — unlike ALT which is liver-specific.

Normal Range

• 10–40 U/L for adults
• Mildly elevated: 1–3× upper limit
• Markedly elevated: more than 3× upper limit

Causes of Elevated AST

• Liver disease — hepatitis, cirrhosis, fatty liver
• Heart attack — AST released from damaged cardiac muscle
• Skeletal muscle damage — intense exercise, rhabdomyolysis
• Hemolysis
• Pancreatitis
• Medications — statins, acetaminophen

The AST:ALT Ratio

• Above 2:1 = suggests alcohol-related liver disease
• Below 1:1 = more typical of viral hepatitis or NAFLD
• Approximately 1:1 = nonspecific; interpret clinically

When to Follow Up

• Persistent elevation warrants GGT, viral hepatitis serologies, and liver ultrasound
• Temporary elevations after exercise or illness are common and usually benign