The liver and biliary tree perform vital metabolic and detoxification roles, and disease in these organs produces systemic effects that demand integrated care. This handbook surveys hepatocellular injury, cholestatic disorders, viral and autoimmune hepatitis, cirrhosis, and biliary tract disease with clear diagnostic pathways. It details laboratory interpretation, imaging strategies (ultrasound, CT, MRI), and endoscopic and interventional techniques for biliary pathology. Treatment chapters span antiviral and immunosuppressive regimens, management of portal hypertension, and indications for transplant referral. Emphasis on complications — encephalopathy, coagulopathy, and infection — equips clinicians for acute management and long-term follow-up. Useful for hepatologists, internists, surgeons, and trainees managing complex liver and biliary cases.