Achalasia is a disorder of the esophagus (the tube that carries food from the mouth to the stomach). The esophagus is less able to move food toward the stomach, and the muscle from the esophagus to the stomach does not relax as much as it needs to during swallowing. This relaxation is needed to allow food to enter the stomach.

The main abnormality in achalasia is a failure of the lower esophageal sphincter (a muscular ring at the junction of the esophagus and stomach) to relax during swallowing. The disorder is characterized by loss of the wave-like contraction of smooth muscles that forces food through the digestive tract. (These contractions are called peristalsis.)

Another part of the disorder is lack of nervous stimulation to the esophagus. Causes include damage to the nerves to the esophagus, parasitic infection, cancers, and hereditary factors. Achalasia is a rare disorder, may occur at any age, but is most common in middle-aged or older adults.

• Difficulty swallowing liquids and solids
• Regurgitation (backflow) of food
• Chest pain which may increase after eating or may radiate to the back, neck, and arms
• Unintentional weight loss
• Heartburn
• Cough

An upper GI x-ray test or barium esophagogram may show absence of peristalsis, an enlarged esophagus, and a narrowing at the bottom of the esophagus. The diagnosis is confirmed with esophageal manometry. Physical examination may show signs of anemia.