Alanine aminotransferase (ALT) is an enzyme primarily found in the liver. It plays a crucial role in the metabolism of amino acids, specifically in converting alanine and alpha-ketoglutarate into pyruvate and glutamate. Elevated levels of ALT in the blood can indicate liver damage or disease. Doctors often measure ALT levels through a blood test to assess liver health. High ALT levels may suggest conditions such as hepatitis, fatty liver disease, or liver cirrhosis. Monitoring ALT is important for diagnosing and managing liver-related health issues.