What is the FIB-4 score?
Last content review 2026-09-23
The short answer
FIB-4 is a first-line estimate of liver-fibrosis risk calculated from age, AST, ALT and platelet count. It helps decide who may need another test; it does not diagnose fibrosis by itself.
What is happening?
The score was originally developed in people with HIV and hepatitis C, then validated and adopted for risk stratification in other chronic liver diseases including MASLD.
Age and clinical context affect interpretation. Indeterminate or elevated results commonly lead to elastography or specialist review.
Why does this matter?
FIB-4 uses routinely available information and can help identify people who should not be reassured by liver enzymes alone.
What does the evidence say?
Current MASLD guidelines recommend a stepwise pathway beginning with FIB-4 in appropriate at-risk adults, followed by a more specific non-invasive test when needed.
Key takeaway
FIB-4 is a triage tool, not a verdict. Ask a clinician to interpret it in your context.
Sources & references
Hepatology
Development of a simple noninvasive index to predict significant fibrosis in patients with HIV/HCV coinfection (2006) · Peer-reviewed study
View original sourceAmerican Association for the Study of Liver Diseases
AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease (2023) · Clinical guideline
View original sourceEASL, EASD and EASO
EASL–EASD–EASO Clinical Practice Guideline on MASLD (2024) · Clinical guideline
View original source
This page is general health education. It is not a diagnosis, and it cannot replace advice from your treating doctor. Never start or stop a prescribed medicine based on what you read here.
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