Many conditions that affect the esophagus, producing obstruction or stagnation (achalasia of the cardia, dermatomyositis, ascending esophageal fibrosis), are physiologically incurable. They are associated in some cases with pulmonary complications. In the beginning the lung changes, caused by overflow from the esophagus, are reversible; later they may be improved, but finally they are permanent. Their relief hinges on the efficacy of operations devised to overcome stagnation of food in the gullet.