Achalasia is an esophageal disorder determined by the lack of peristalsis and dysfunction of the internal esophageal sphincter. The neurons of the esophageal myenteric plexus are destroyed, and this affects distal motility. The incidence changes geographically, being more common between 30 and 60 years of age (very high prevalence). The etiology is unknown; there are multiple hypotheses such as failure of esophageal innervation and degenerative, infectious, and autoimmune theories. The pathophysiology involves simultaneous changes that influence esophageal peristalsis and relaxation of the lower esophageal sphincter. The most frequent symptoms are dysphagia, heartburn, regurgitation, chest pain, and weight loss. Endoscopy, barium study, and esophageal manometry, among other tests, are used to diagnose this disorder. Conventional treatment includes endoscopic pneumatic dilatation and Heller myotomy with partial fundoplication. Physiotherapy focuses, above all, on the prevention of respiratory complications to avoid risks to the patient’s life, with specific exercises for swallowing and breathing techniques.