ALT (Alanine Aminotransferase) test is a blood test that measures the level of ALT enzyme in the blood. ALT is an enzyme primarily found in the liver, essential for converting proteins into energy for liver cells. The test is often used to assess liver health and detect liver damage. Elevated levels of ALT in the blood can indicate liver injury or inflammation, as the enzyme leaks into the bloodstream when liver cells are damaged. Therefore, the ALT test is a key component in diagnosing liver conditions such as hepatitis, cirrhosis, and liver damage from medications, alcohol use, or other toxins. Monitoring ALT levels helps in the early detection and management of liver disease.