What is the normal reference range for ALT?

What is the normal reference range for ALT?

• A. 10-50
• B. 7-56
• C. 0-10
• D. 60-100

Answer: (B)

ALT is a liver-specific enzyme, and its level in the blood reflects hepatocellular health. For most adults, the normal reference range is about 7 to 56 units per liter (U/L). This window is widely used, though exact cutoffs can vary slightly by lab, method, and patient factors like age and sex. Values within this range generally indicate no meaningful hepatocellular injury, while higher values suggest liver cell damage—from hepatitis, fatty liver disease, medication effects, or other liver conditions. The other ranges listed fall outside the typical adult reference for ALT, which is why 7-56 U/L is the best choice.

ALT is a liver-specific enzyme, and its level in the blood reflects hepatocellular health. For most adults, the normal reference range is about 7 to 56 units per liter (U/L). This window is widely used, though exact cutoffs can vary slightly by lab, method, and patient factors like age and sex. Values within this range generally indicate no meaningful hepatocellular injury, while higher values suggest liver cell damage—from hepatitis, fatty liver disease, medication effects, or other liver conditions. The other ranges listed fall outside the typical adult reference for ALT, which is why 7-56 U/L is the best choice.