Fatty liver is usually divided into grades 1–3 based on how much of the liver is filled with fat (steatosis), and may progress to non‑alcoholic steatohepatitis (NASH), fibrosis, and finally cirrhosis if not treated. Grade 1 involves mild fat accumulation (<33%), grade 2 shows moderate fat (33–66%) with inflammation, and grade 3 is severe (>66%) often with early scarring; advanced stages include stage 3–4 fibrosis and cirrhosis.







