<unk>  defined as abnormal blood loss from the esophagus (the tube that connects the mouth and stomach), the stomach, or the duodenum (the first foot of the small intestine that follows the stomach).
Upper gastrointestinal bleeding
Lower gastrointestinal bleeding
Gastrointestinal varices
Oral ulcer
Gastrointestinal bleeding
Internal bleeding
Nosebleed
Peptic ulcer