Diagnosing cirrhosis has evolved from mandatory liver biopsy (Metavir F4) to validated non-invasive methods. FibroScan (transient elastography) measures liver stiffness using ultrasound-based shear wave velocity: <7 kPa is normal, 7-12.5 kPa suggests significant fibrosis, >12.5 kPa suggests cirrhosis (with >95% NPV for ruling out advanced fibrosis). Serum biomarker panels include FIB-4 (combining age, AST, ALT, platelets; >3.25 suggests advanced fibrosis), APRI (AST-to-platelet ratio index), and enhanced liver fibrosis (ELF) test. The Child-Pugh classification (A=5-6, B=7-9, C=10-15) uses bilirubin, albumin, INR, ascites, and encephalopathy to stage functional severity. The MELD score (using bilirubin, INR, creatinine) predicts 3-month mortality and determines transplant priority.