<prompt> Poal hypeension is defined as, hepatic venous pressure gradient HVPG greater than5 mm of hg10 mm of Hg15 mm of Hg20 mm of Hg  <response>: Poal hypeension is defined as the elevation of the hepatic venous pressure gradient HVPG to 5 mmHg. Poal hypeension is caused by a combination of two simultaneously occurring hemodynamic processes: 1 Increased intrahepatic resistance to the passage of blood flow through the liver due to cirrhosis and regenerative nodules, and 2 Increased splanchnic blood flow secondary to vasodilation within the splanchnic vascular bed. Poal hypeension is directly responsible for the two major complications of cirrhosis: variceal haemorrhage and ascites.Ref: Harrison 19e pg: 2063 