Hepatic Portal Hypertension

Blood clots can cause obstruction of the hepatic portal vein, but, more commonly, portal hypertension is the result of cirrhosis, in which the liver tissue is replaced by scar tissue in response to damage from a variety of causes, including chronic alcohol intoxication or hepatitis C.
As blood flow is obstructed, blood pressure in the hepatic portal system increases, and venous engorgement occurs. These enlarged veins form thin-walled varices, which are susceptible to trauma.