Causes

Esophageal varices sometimes form when blood flow to your liver is blocked, most often by scar tissue in the liver caused by liver disease. The blood flow begins to back up, increasing pressure within the large vein (portal vein) that carries blood to your liver.

This increased pressure (portal hypertension) forces the blood to seek other pathways through smaller veins, such as those in the lowest part of the esophagus. These thin-walled veins balloon with the added blood. Sometimes the veins rupture and bleed.

Causes of esophageal varices include:

• Severe liver scarring (cirrhosis). A number of liver diseases — including hepatitis infection, alcoholic liver disease, fatty liver disease and a bile duct disorder called primary biliary cirrhosis — can result in cirrhosis.
• Blood clot (thrombosis). A blood clot in the portal vein or in a vein that feeds into the portal vein (splenic vein) can cause esophageal varices.
• Parasitic infection. Schistosomiasis is a parasitic infection found in parts of Africa, South America, the Caribbean, the Middle East and East Asia. The parasite can damage the liver, as well as the lungs, intestine, bladder and other organs.