What are the most common reasons people develop portal hypertension?

Cirrhosis. Portal hypertension can be caused by cirrhosis, clots which can develop in the portal vein and the parasite, schistosomiasis. Sometimes medications can be used to reduce portal pressure. If you think you have portal hypertension, you should see a physician.
Cirrhosis. The first three causes are cirrhosis, cirrhosis, and cirrhosis. Rare causes are portal vein thrombosis and, in asia, certain parasitic diseases.