In short

ALT and AST are proteins that leak into the blood when liver cells are irritated. They are clues, not a full answer.

1 min read

Raised enzymes can be a sign of fatty liver, but many people with fatty liver, even with scarring, have normal enzymes.

So normal enzymes do not rule out liver disease. Doctors use them inside scores like FIB-4, together with age and platelets.

Sources

EASL–EASD–EASO Clinical Practice Guidelines on the management of MASLD. J Hepatol 2024;81:492–542. Link
Rinella ME, et al. AASLD Practice Guidance on the clinical assessment and management of NAFLD. Hepatology 2023;77:1797–835. Link

Last updated 2026-10-03. Based on international and Saudi guidelines. Education only: it does not replace your doctor. Read the disclaimer.

What are liver enzymes (ALT and AST)?