Esophageal webs are thin, membranous mucosal tissue covered by squamous epithelium that protrudes into the esophageal lumen. An esophageal web is often asymptomatic but can be characterized by dysphagia, particularly to solid foods. The esophageal luminal narrowing is most typically focal, located most commonly in the hypopharynx and cervical esophagus, although a web can be located anywhere in the esophagus.

Esophageal webs are either acquired (most common) or congenital (extremely rare). Acquired esophageal webs are more commonly thin and associated with a variety of underlying medical conditions including, but not exclusively limited to, Zenker diverticulum, epidermolysis bullosa, bullous pemphigoid, pemphigus vulgaris, and chronic graft-versus-host disease following bone marrow transplantation. Plummer-Vinson syndrome is the triad of iron deficiency anemia, dysphagia, and cervical esophageal web, typically presenting in women of Northern European descent in their fourth to seventh decade of life, and is an important risk factor for developing esophageal or pharyngeal squamous cell carcinoma.

The incidence of esophageal webs is hard to determine as the majority of patients are asymptomatic. Congenital esophageal webs are often associated with dysphagia in the neonatal or early childhood years. Acquired webs can be either discovered incidentally on upper endoscopy or barium swallow or diagnosed in patients complaining of dysphagia who undergo imaging or endoscopic evaluation.