Esophageal varices nearly always rupture at or just above the gastro-esophageal junction. Mucosal changes on top of the varices, the so-called red colour sign, are found in the majority of patients with a positive bleeding history. An increase of intraabdominal pressure and consequently a sudden pressure rise in the varices is thought of as a trigger cause. The larger the esophageal varices the higher the intravariceal and the transmural varix pressures. The portal pressure in patients with portal hypertension is subjected to considerable changes. Therefore, hemodynamic measurements at rest may have a prognostic value with regard to predisposition to hemorrhage, but they are less significant than endoscopic parameters. Disturbances of blood hemostasis and ascites indicating an impaired liver function are essential predisponable factors for the onset of bleedings. A peptic lesion caused by acid gastric-esophageal reflux is of less importance for the occurrence of variceal hemorrhage.