The clinical indication for urgent endoscopy with combined diagnosis and treatment is bleeding severe enough to warrant urgent medical attention. Stigmata of ulcer hemorrhage are utilized as a guide to endoscopic therapy. Active arterial bleeding, nonbleeding visible vessels, and adherent nonbleeding clots are always treated endoscopically. In randomized trials, patients with these "major stigmata" had better outcomes from endoscopic therapies than with medical therapies alone. Flat spots, gray or black sloughs, and clean ulcer bases are not treated endoscopically, since medical therapy alone affords good outcome. The current recommendation is to treat major stigmata of hemorrhage endoscopically for the initial bleeding episode and a second time for rebleeding before considering ulcer surgery. Clinical presentation and comorbidity and the endoscopic appearance of the ulcer (i.e., stigmata of hemorrhage) of patients with UGI bleeding are used to determine the subsequent level of care (e.g., discharge or ward or intensive care).