Summary

• An oesophageal motor disorder characterised by a loss of peristalsis in the distal third of the oesophagus and failure of the lower oesophageal sphincter to relax in response to swallowing.
• The most common presenting symptoms are dysphagia to solids and liquids, regurgitation, and retrosternal pain. These can be slowly progressive over months or years.
• The first investigation for any patient with dysphagia is endoscopy to exclude malignancy, but subsequent barium swallow studies and oesophageal manometry are usually required to establish the diagnosis of achalasia.
• Treatment is symptomatic, not curative, and is primarily aimed at relieving dysphagia; options include pharmacological, endoscopic, and surgical procedures.