Inadequate relaxation of the esophageal sphincter (e.g., caused by achalasia or spastic motility) and increased intraluminal pressure → outpouching of the esophageal wall → pulsion diverticulum
Usually a false diverticulum
Common sites
Upper esophageal sphincter (UES) → pharyngoesophageal pulsion diverticulum (e.g., Zenker diverticulum, between the thyropharyngeal and cricopharyngeal)