AST in a blood test stands for aspartate aminotransferase , an enzyme primarily found in the liver but also present in the heart, muscles, kidneys, brain, and other tissues. It plays a role in amino acid metabolism. Normally, only low levels of AST are found in the blood. When cells that contain AST are damaged, such as liver cells, AST leaks into the bloodstream, causing elevated blood levels

. The AST blood test is mainly used to:

• Assess liver health and detect liver damage or disease (e.g., hepatitis, cirrhosis, liver cancer)

• Help diagnose other conditions involving damage to the heart, muscles, or other organs that contain AST

• Monitor the effectiveness of treatment for liver conditions

Because AST is found in multiple organs, the test is often ordered alongside other liver enzymes, such as ALT (alanine aminotransferase), to better pinpoint liver-specific issues

. Normal AST levels typically range from about 8 to 33 units per liter (U/L), though exact reference ranges can vary by laboratory and patient factors

. Elevated AST levels may indicate liver inflammation, injury, or other organ damage, while low levels are generally less concerning

. In summary, an AST blood test measures the level of the enzyme aspartate aminotransferase in your blood and is primarily used to evaluate liver function and detect liver or other tissue damage