What is the most common cause of portal hypertension?

• A. Right heart failure
• B. Budd-Chiari syndrome
• C. Cirrhosis
• D. Portal vein thrombosis

Answer: (C)

Portal hypertension happens when the pressure in the portal venous system rises, and the most common cause is cirrhosis. In cirrhosis, fibrotic scarring and nodular regeneration distort the liver’s architecture, greatly increasing resistance to blood flow through the liver. That intrahepatic resistance elevates portal venous pressure and leads to clinical signs like varices and ascites. The other conditions can cause portal hypertension but are less frequent: right heart failure or congestive hepatopathy raises venous pressures but is not the primary driver; Budd-Chiari syndrome is hepatic venous outflow obstruction; and portal vein thrombosis is a prehepatic cause. So cirrhosis remains the leading cause.