This document discusses portal hypertension and its causes, effects, diagnosis, and treatment. It begins by describing portal vein anatomy and how portal pressure is normally measured. The main causes of portal hypertension are then outlined as being pre-hepatic (portal vein obstruction), intra-hepatic (liver disease), or post-hepatic (hepatic vein issues). Key sequelae include portosystemic collaterals, splenomegaly, gastrointestinal congestion, bleeding varices, and ascites. Investigations focus on liver function tests, detecting varices, and assessing severity using the Child-Pugh classification. Treatment involves resuscitation, preventing encephalopathy, and procedures like sclerotherapy, banding, drugs,