Expanded and protruding (dilated) veins (just like varicose veins but internal) that run along the wall under the lining of the upper part of the stomach and lower end of the gullet. If they rupture or break they will bleed heavily (variceal bleeding). They are usually found in patients with cirrhosis or other forms of portal hypertension.

Because of this risk of bleeding, they are best dealt with prophylactically. This means that all patients with cirrhosis or another reason to suspect varices ar present should under go endoscopy. If varices are found it is then relatively easy to treat them as part of a planned procedure.