Achalasia is a medical condition that affects the esophagus, the muscular tube that connects the throat to the stomach. In this condition, the muscles of the esophagus and the lower esophageal sphincter (LES) do not work properly, leading to difficulty in swallowing food and liquids.
Normally, the muscles of the esophagus contract in a coordinated way to push food and liquids down to the stomach. The LES, a ring of muscle at the bottom of the esophagus, relaxes to allow food to enter the stomach and then tightens to prevent stomach contents from flowing back up into the esophagus. In achalasia, the esophagus and LES fail to contract and relax properly, leading to a buildup of food and liquid in the esophagus.
The exact cause of achalasia is not known, but it is believed to be related to damage or degeneration of the nerves that control the esophagus and LES. Symptoms of achalasia include difficulty swallowing, chest pain, regurgitation of food or liquid, heartburn, and weight loss.
Diagnosis of achalasia is usually made through a combination of medical history, physical exam, and tests such as esophageal manometry, which measures the pressure in the esophagus and LES, and an upper endoscopy, which allows the doctor to examine the esophagus and stomach with a camera.
Treatment of achalasia typically involves the use of medications to relax the LES, such as nitrates or calcium channel blockers, or injection of botulinum toxin into the LES to weaken the muscle. Surgery may also be recommended, including a procedure called a Heller myotomy, in which the muscles of the LES are surgically cut to allow food and liquid to pass more easily into the stomach.