Portal hypertension

A pathological increase in pressure within the portal venous system, defined by an elevated hepatic venous pressure gradient (≥6 mm Hg) between the portal vein and hepatic/inferior vena cava pressures. Possible causes are intrahepatic factors (cirrhosis, schistosomiasis, hemochromatosis, Wilson's disease), prehepatic (portal vein thrombosis), and posthepatic (Budd-Chiari syndrome, heart failure).