Hematemesis

Hematemesis refers to the vomiting of blood by the patient, caused by acute bleeding from the upper gastrointestinal tract (esophagus, stomach, duodenum, jejunum after gastrojejunostomy, pancreas, and biliary tract). However, it can also be seen in certain systemic diseases. Before confirming hematemesis, bleeding from the oral cavity, nose, pharynx, and larynx, as well as hemoptysis, must be excluded. Hematemesis and melena are common major symptoms of gastrointestinal bleeding in neonates. In general, bleeding from the digestive tract above the suspensory muscle of the duodenum (also known as the ligament of Treitz) is called upper gastrointestinal bleeding, mainly manifested as hematemesis; while lower gastrointestinal bleeding is mainly manifested as hematochezia. When the amount of bleeding in the lower gastrointestinal tract is large or the intraluminal pressure is higher than the intragastric pressure, bloody fluid can reflux into the stomach and esophagus, which may also cause hematemesis under different circumstances. Conversely, when upper gastrointestinal bleeding exceeds 3 ml, black stools may also occur. That is, black stools may occur without hematemesis, whereas hematemesis is often accompanied by black stools.