Aspartate aminotransferase (AST)

AST is a liver enzyme and is measured to assess diseases of the liver. AST can also be performed to assess the damage the heart muscle after a heart attack.

Aspartate aminotransferase (AST) Overview

Reviewed: April 22, 2014

Aspartate aminotransferase (AST) is an enzyme found in the heart, liver, and muscle. After injury or death to cells, AST becomes elevated. This test is performed when there has been damage to the heart muscle during a heart attack as well as used to assess liver damage.

AST is measured in Units per liter (U/L). The normal ranges for AST are the following:

  • Males: 0 - 37 U/L
  • Females: 0 - 31 U/L


Blood draw


Fasting is not required before the test

What the results mean

Elevated AST may be seen with acute renal disease, heart attack, inflammation of the liver, cirrhosis, and pancreatitis.

Low levels of AST may be seen during dialysis and pregnancy. Low levels of AST may be caused by diabetic ketoacidosis and thiamine (vitamin B1) deficiency.