Esophageal achalasia is a rare disease of unknown origin in which the sphincter in the esophagus does not relax, preventing the passing of food. The main symptom is dysphagia (or difficulty swallowing) followed by regurgitation. Endoscopy allows us to suspect the diagnosis of the disease by the detection of esophageal dilatation. Esophageal manometry, which studies the pressure in the sphincter, confirms the diagnosis by showing the absence of contraction. Initial treatment involves muscle relaxants, but support with endoscopy or surgery is frequently necessary.