ALT – SGPT (Alanine Aminotransferase / Serum Glutamate Pyruvate Transaminase) Sample Type: Serum Description: ALT (also known as SGPT) is an enzyme mainly found in the liver. It plays a key role in amino acid metabolism and is released into the bloodstream when liver cells are damaged. Purpose of Test: Measures the level of ALT in the blood to: Assess liver function Detect liver damage or inflammation Monitor liver disease or the effects of medications Normal Range (may vary slightly by lab): Adults: 7 to 56 units per liter (U/L) Causes of Elevated ALT: Hepatitis (viral or autoimmune) Fatty liver disease Cirrhosis Alcohol abuse Liver injury from drugs or toxins Muscle damage (less common) Clinical Significance: An elevated ALT level is a sensitive indicator of liver cell injury. It is often one of the first enzymes to rise in response to liver damage. Note: ALT is usually interpreted alongside other liver function tests such as AST, ALP, and bilirubin for accurate diagnosis.