How high is too high for ALT?

Above 40 warrants context; sustained above 60-80 in non-athletes warrants imaging and workup for NAFLD or viral hepatitis.

Alanine Aminotransferase (ALT)

Quick answer

What is Alanine Aminotransferase (ALT)?

ALT is the most liver-specific of the standard liver enzymes. Elevated ALT signals hepatocyte damage — most commonly from NAFLD (fatty liver) in men 25-55, alcohol, medications, or viral hepatitis.

Units:: U/L
Reference range:: <40 U/L (men)
Sample:: Venous blood (serum)

Category: Liver
Units: U/L
Reference range: <40 U/L (men)

What does a high Alanine Aminotransferase result mean?

Fatty liver (NAFLD), alcohol, viral hepatitis, drug-induced, intense exercise can transiently elevate.

What does a low Alanine Aminotransferase result mean?

Usually benign.

Why does Alanine Aminotransferase matter?

NAFLD is the most common liver issue in metabolically unhealthy men. Often the first sign before HbA1c shifts.

FAQs

How high is too high for ALT?: Above 40 warrants context; sustained above 60-80 in non-athletes warrants imaging and workup for NAFLD or viral hepatitis.

References

[1]ACG Clinical Guideline: Evaluation of Abnormal Liver ChemistriesPubMed / Am J Gastroenterol
[2]Clinical Methods: The History, Physical, and Laboratory ExaminationsNCBI Bookshelf

Want Alanine Aminotransferase interpreted in the context of your full panel? Every FORM bloodwork tier covers it, with an MD walking you through the result.

Message on WhatsApp

Related liver markers

Gamma-Glutamyl Transferase →