Illustration of an oesophagus affected by varices (dilated blood vessels, blue) due to liver cirhhosis. Here, the veins in the wall of the esophagus are dilated. Oesophageal varices are extremely dilated sub-mucosal veins (varices) in the lower third of the oesophagus. They are most often a consequence of portal hypertension - high blood pressure in the portal vein and its tributaries.