Achalasia is a rare disease of the muscle of the esophagus (swallowing tube). The term achalasia means "failure to relax" and refers to the inability of the lower esophageal sphincter (a ring of muscle situated between the lower esophagus and the stomach) to open and let food pass into the stomach. As a result, patients with achalasia have difficulty in swallowing food. | What is achalasia Achalasia is a rare disease of the muscle of the esophagus swallowing tube . The term achalasia means failure to relax and refers to the inability of the lower esophageal sphincter a ring of muscle situated between the lower esophagus and the stomach to open and let food pass into the stomach. As a result patients with achalasia have difficulty in swallowing food. ACHALASIA CAUSE The specific cause of achalasia is unknown. However patients with achalasia have two problems in the esophagus the tube that carries food from the mouth to the stomach . The lower two-thirds of the esophagus does not propel food toward the stomach properly. The lower esophageal sphincter LES a circular band of muscle that lies at the junction of the esophagus and the stomach does not function correctly. Normally the LES helps prevent food from flowing backwards from the stomach into the esophagus. The LES should relax in response to swallowing to allow food to enter the stomach. In people with achalasia the LES fails to relax creating a barrier that prevents food and liquids from passing into the stomach . One theory is that the nerve cells responsible for relaxation are destroyed by an unknown cause. Damage to the LES and esophagus causes large volumes of food and saliva to accumulate in the esophagus. Most people can initially compensate for this. Eventually the barrier progresses to the point where food and saliva cannot reliably enter the stomach. As a result food and saliva build up in the esophagus. ACHALASIA SYMPTOMS The most common symptom of achalasia is difficulty swallowing liquids or solids . This problem begins slowly and progress gradually many people do not seek help until symptoms are advanced. Some people compensate by eating more slowly and using specific maneuvers such as lifting the neck or throwing the shoulders back to improve emptying of the esophagus. Other symptoms can include chest pain regurgitation of swallowed food and liquid heartburn .