Hematemesis is the vomiting of blood.

• Source is generally thought to be the upper GI tract, typically above the suspensory muscle of the duodenum

• Mallory-Weiss syndrome, bleeding tears in the esophageal mucosa, usually caused by prolonged and vigorous retching
• Irritation or erosion of the lining of the esophagus or stomach
• Vomiting of ingested blood after hemorrhage in the oral cavity, nose or throat
• Vascular malformations of the GI tract, e.g. bleeding gastric varices or intestinal varices
• Tumors of the stomach or esophagus
• Radiation poisoning
• Viral hemorrhagic fevers
• Gastroenteritis
• Gastritis
• Peptic ulcer
• Chronic viral hepatitis
• Intestinal schistosmiasis, caused by the parasite schistosoma mansoni
• Hx of smoking
• Iatrogenic injury, invasive procedure e.g. endoscopy or transesophageal echo
• Zollinger-Ellison syndrome, severe peptic ulcer
• Atrio-esophageal fistula
• Yellow fever

• It is always an important sign
• Vomiting blood volumes >5.5L can be life threatening

• Hemoptysis (COUGHING up blood, which is more common)