Why would vomit blood in patients with cirrhosis

Cirrhosis, as portal hypertension, often a few traffic branch, its main four: (1) of gastric and esophageal under the traffic branch. (2) the bottom of the rectum and anal canal traffic branch. (3) abdominal wall traffic branch. (4) retroperitoneal traffic branch.  Traffic more than four-to lower esophageal and gastric traffic in support of the most important. Under normal circumstances, these are very small traffic branch, not the blood flow. When returning blocked portal vein hypertension, because of their own free portal vein valve, reversible portal blood flow in the four-traffic due to traffic branch expansion. Lower esophageal and gastric vein as the pressure difference larger vein in the first Nuzhang. Nuzhang vein falling into the esophagus or stomach parts of the mucous membrane thinning, vulnerable to rupture and cause bleeding injury. Such as food mechanical injury, gastric reflux of chemical injury, as well as coughing, vomiting, constipation, such as abdominal pressure increases, can the portal pressure suddenly increased, leading to the bleeding Nuzhang vein, is an acute upper gastrointestinal bleeding, Performance for hematemesis or blood in the stool. About 2 / 3 of life in patients with cirrhosis at least one gastrointestinal bleeding. Hematemesis and / or blood in the stool, cirrhosis is the common clinical manifestations. Cirrhosis of the main reasons for upper gastrointestinal bleeding for: 1. Esophageal and gastric variceal bleeding: the first of the bleeding, 60% to 75% for hematemesis clinical performance and / or blood in the stool, the amount of bleeding, with varying degrees of hemorrhagic shock, the dangerous condition. It is worth noting that the site can be associated with bleeding in other parts hemorrhage, endoscopy is the only reliable method of diagnosis. 2. Peptic ulcer bleeding: 15% to 30% of major performance will be for black and / or blood will rarely lose bloody shock. 3. Portal hypertension gastropathy bleeding: 10% to 20% less bleeding, clinical and peptic ulcer bleeding difficult to identify. Other: cirrhosis patients with reflux esophagitis can also cause bleeding, a very small number of patients with esophageal cancer can be combined, stomach bleeding, and so on.