Achalasia is a benign (non-cancerous) condition of the oesophagus that causes difficulty swallowing. It is caused by a problem with the nerves and muscles of the oesophagus that leads to failure of the lower end of the oesophagus to relax with swallowing. This failure prevents the normal passage of food through the lower oesophagus and causes symptoms of dysphagia (difficulty swallowing) or heartburn symptoms similar to reflux. The symptoms usually progress slowly with time and have often been present for years before the sufferer decides to see a doctor for it.
Treatment aims at improving swallowing by decreasing the pressure, or tension, in the lower oesophageal sphincter. This can be achieved by injection of a chemical to relax the muscle, by stretching the muscle fibres (dilation) or by cutting the muscle fibres (myotomy) through either keyhole surgery or a procedure known as Per-Oral Endoscopic Myotomy (POEM).
None of these treatments fix the underlying problem with the nerves, but aim to improve the symptoms which are bothering the individual.