Achalasia Q and A
What is achalasia?
Achalasia is a primary motor disorder of the esophagus in which the pressure at the lower esophageal sphincter (LES) is abnormally high and does not relax with swallowing. The term is derived from the Greek word for non-relaxing. As a result of achalasia, it is difficult to swallow food. This may only affect solid food at first, but with time the area gets tighter, and even swallowing liquids becomes a problem. Over time, the esophagus dilates because food cannot get past the LES.
What is the LES?
The LES, or lower esophageal sphincter, is an area of esophageal muscle at the end of the esophagus that normally is contracted and closes off the esophageal lumen. When we swallow, the upper esophagus contracts and the LES relaxes, allowing food, liquid and/ or saliva to pass into the stomach. In achalasia, the LES pressure is much higher than normal, and, more importantly, the LES does not relax when the person swallows.
What causes achalasia?
The disease is idiopathic in the United States-we do not know why it happens. What is clear is that the nerves to the lower esophagus do not work properly. In South America the disease is most often due to an infestation by a parasite, a trypanosome. This disease, known as Chagas disease, does not occur in the United States.
How common is achalasia?
Achalasia is an uncommon disorder in the United States; less than one person in 100,000 develops it each year. About 8 people in 100,000 have the disease in the United States. It usually occurs in people between 20 and 40 years of age, with equal frequency in men and women. There appears to be no genetic basis for this disease; only 5 cases of achalasia occurring in a parent and child have been reported in the United States.