Normal ALT results should range from 7 to 55 U/L, according to Mayo Clinic. This range may differ slightly across the age and gender of patients and the laboratory of analysis and may be affected by certain foods and medications.
An ALT test determines the amount of alanine transaminase in the blood. Since the enzyme is largely concentrated in the liver and released into the bloodstream due to injury, such tests are considered a good indicator of liver health.
Increased ALT levels may be the result of cirrhosis, hepatitis, hemochromatosis, mononucleosis, pancreatitis, death of liver tissue, lack of blood flow to the liver or a number of other conditions.