📚 Fib 4 計算機

The Fibrosis-4 (FIB-4) index is a simple, non-invasive scoring tool used to estimate the amount of scarring (fibrosis) in the liver. It combines four routinely available values — patient age, two liver enzymes (AST and ALT), and platelet count — into a single number. Originally developed for patients with viral hepatitis, it is now widely applied to screen for advanced fibrosis in conditions such as non-alcoholic fatty liver disease (NAFLD/MASLD). This tool is for educational use and does not replace clinical judgement.

Enter the patient's age in years, the AST and ALT enzyme levels in U/L, and the platelet count in 10⁹/L (the same as ×10³/µL). Press calculate to get the FIB-4 score along with its risk category. Make sure lab values come from the same blood draw for the most meaningful result.

Age and AST raise the score, while higher platelets and ALT lower it. The logic reflects that liver damage tends to raise AST relative to ALT and reduces platelet production, so a higher score signals more likely fibrosis.

For a 55-year-old with AST = 40, ALT = 30 and platelets = 150: numerator = 55 × 40 = 2200; denominator = 150 × √(30) = 150 × 5.4772 = 821.58;

This falls in the indeterminate range (1.45–3.25), suggesting further evaluation may be warranted.