NAFLD Activity Score (NAS)
Histological scoring system for NAFLD severity on liver biopsy. Scores steatosis, lobular inflammation, and hepatocyte ballooning. NAS ≥5 is associated with NASH diagnosis.
Score interpretation
NAS 0–2 — unlikely to be NASH
→ Diagnose as simple steatosis or borderline; lifestyle modification; annual follow-up
NAS 3–4 — borderline NASH
→ Clinical context required for NASH diagnosis; address metabolic risk factors; consider repeat biopsy if disease progresses
NAS ≥5 — consistent with NASH diagnosis
→ Treat NASH: weight loss ≥10%, exercise, vitamin E (non-diabetics), consider pharmacotherapy (GLP-1 agonists); hepatology referral
Interpretation bands for the NAS. Apply clinical judgement and local guidance.
References
- Kleiner DE et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005;41(6):1313–1321.
Related
Curated clinical cross-links plus same-class fallbacks.
- Colchicine (Pericarditis / Post-MI Inflammation) · Pericarditis / Coronary Inflammation
- Pindolol · Non-selective β-blocker (with intrinsic sympathomimetic activity)
- Methotrexate (Dermatology — Psoriasis) · Disease-Modifying Antirheumatic / Immunosuppressant
- Dexamethasone · Corticosteroid — ENT Inflammation / Croup
- Acetazolamide (Ménière's Disease) · Carbonic Anhydrase Inhibitor (Diuretic)
- Zinc acetate · Zinc salt (Wilson's disease)
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.