Boerhaave syndrome is a transmural perforation of the esophagus caused by a sudden, dramatic increase in intraesophageal pressure against a closed glottis, most commonly occurring during forceful vomiting or retching. Unlike iatrogenic esophageal perforations (which account for the majority of all esophageal perforations and typically occur during endoscopy, dilation, or transesophageal echocardiography), Boerhaave syndrome represents a spontaneous, full-thickness rupture that carries a mortality rate of 20-40% even with treatment, and approaches 100% without surgical intervention. Understanding the anatomy of the esophagus is critical for appreciating why this condition is so dangerous. The esophagus is unique among gastrointestinal structures in that it lacks a serosal layer -- it has only mucosa, submucosa, and muscularis propria (inner circular and outer longitudinal muscle layers) surrounded by adventitia. The absence of a serosa means there is no additional protective barrier to contain a perforation, allowing esophageal contents (gastric acid, digestive enzymes, food particles, and bacteria) to communicate directly with the mediastinum and pleural spaces. The left posterolateral distal esophagus, approximately 2-3 cm above the gastroesophageal junction, is the most common site of rupture (approximately...