ALT (alanine transaminase) is an enzyme that is normally found in the liver and small amounts in other body tissues, such as the heart and muscle cells. High levels of ALT in the blood can indicate liver damage or disease.
What Causes High ALT Levels?
High ALT levels may be caused by a variety of medical conditions, including viral hepatitis, alcoholic liver disease, nonalcoholic fatty liver disease, and cirrhosis. Other causes include certain medications, such as statins, which are used to lower cholesterol, and anabolic steroids, which are used to build muscle.
How Common Is High ALT?
High ALT levels are relatively common, especially among people with chronic liver diseases such as hepatitis C or alcoholic liver disease. According to the Centers for Disease Control and Prevention (CDC), about 10 percent of adults in the United States have elevated ALT levels in their blood tests.
