Abstract
This case report presents a 34-year-old Japanese man with hematemesis who was ultimately diagnosed with gingival bleeding due to periodontitis via esophagogastroduodenoscopy. Although endoscopic examination revealed no gastrointestinal lesions, persistent bleeding from the gums was observed, highlighting the need to consider non-gastrointestinal sources of bleeding in such scenarios. Heavy alcohol consumption likely contributed to poor oral health and increased the risk of oral bleeding. This case emphasizes the importance of thorough endoscopic evaluation of the oral and pharyngolaryngeal regions, particularly when common gastrointestinal sources of bleeding are excluded. A comprehensive diagnostic approach is essential to avoid overlooking less common causes of bleeding.