What is chronic hepatitis, and what are its main causes?

Chronic hepatitis is hepatitis (hepatic inflammation) lasting more than 6 months. Main causes: chronic viral hepatitis (B, C, D), non-alcoholic fatty liver disease (NAFLD/NASH, now termed MASLD/MASH), autoimmune hepatitis, and drug-induced hepatitis.

Clinical relevance. Defining chronic hepatitis and its differential drives a structured search for a treatable cause.

More Detail

Chronic hepatitis

Chronic hepatitis is a clinicopathological syndrome, not a single disease, and identifying the cause is the key to management.

Definition

• Hepatic inflammation lasting more than 6 months.
• Chronic viral hepatitis is the principal cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma worldwide.

Main causes

• Chronic viral hepatitis: hepatitis B (with or without D) and hepatitis C.
• Metabolic dysfunction-associated steatotic liver disease (MASLD/NAFLD), including MASH/NASH.
• Autoimmune hepatitis.
• Drug-induced: isoniazid, methotrexate, methyldopa, nitrofurantoin, amiodarone, tamoxifen.
• Hereditary (Wilson's disease) and other rarer causes.

First step

• Establish the cause with serology (HBV/HCV), metabolic risk assessment, autoantibodies, and a drug history.