Achalasia - Achalasia is a disease of the swallowing tube (esophagus) in which food does not move normally from the swallowing tube into the stomach. While the cause is unknown, the result is that the valve at the bottom of the swallowing tube where it joins the stomach does not relax adequately when food needs to go by during swallowing. Over time, this functional blockage at the end of the swallowing tube causes the swallowing tube to dilate and to lose its ability to propagate a wave of contraction down towards the stomach. It is a rare disorder, which can occur at any age but is most common in middle-age or older adults. In other countries, it is associated with a parasitic disease called Shagus disease.

The symptoms of achalasia are difficulty swallowing liquids and eventually solids. It is often associated with regurgitation of food, chest pain (particularly when eating), unintentional weight loss, heartburn and cough. While achalasia is a rare disease, there are operations which can significantly improve the problem.