Phase 1 · Understand the Body — Why the disease behaves the way it does.
The One-Line Truth
The whole disease in one chain
Everything on this page exists to explain this line.
A virus sneaks into liver cells, your immune system fights back hard, and the battle makes you tired, yellow, and sick—but most people win and heal completely.
Factory Under Siege
Your liver is a chemical factory humming along, processing raw materials (blood nutrients) into products (proteins, clean blood) 24/7. A virus is like a saboteur who sneaks into the factory, hijacks the machinery (ribosomes and enzymes inside hepatocytes), and uses it to make bombs (virus copies). Your immune system is the security team—it spots the sabotage, but to stop the bomb-maker, it has to blow up the whole workstation (kill the infected hepatocyte with cytotoxic T cells), which damages the factory floor. The yellow dye (bilirubin) that normally gets packaged and shipped out (into bile) backs up and spills everywhere (into blood and urine) because the damaged assembly line can't process it. If the sabotage goes on for years (chronic infection), the factory gets scarred from all the explosions, walls thicken (fibrosis becomes cirrhosis), and fewer workers can do the job, until one day the factory can barely function.
AASLD Hepatitis B Guidance 2018 · AASLD-IDSA HCV Guidance 2023 · CDC Viral Hepatitis Surveillance and Prevention · WHO Guidelines on Hepatitis B and C Testing and Treatment 2023 · reviewed 2026-07-07