Mallory-Weiss tear is upper gastrointestinal bleeding produced by longitudinal mucosal lacerations (tears) at the gastroesophageal junction (cardiac sphincter). Initiation of the tear (and bleeding) can occur after a sudden rise in intragastric pressure or gastric prolapse into the esophagus.

The incidence of Mallory-Weiss tear accounts for about 15% of all cases of upper gastrointestinal bleeding. Males are affected more than females at a rate of 2:1 to 4:1.

Mallory-Weiss tear occurs as a result of large, rapid, transient, transmural pressure gradient generation across the area of the gastrointestinal junction. This injury may be precipitated by retching or vomiting or by violent prolapse or intussusception of the upper stomach into the lower esophagus.