Achalasia:
Translating to "failure to relax", esophageal achalasia is a rare chronic disease where the nerves in the esophagus and lower esophageal sphincter (LES) degenerate, hindering peristalsis and the opening of the LES. Food is not allowed to pass to the stomach, and instead gathers in the esophagus, which dilates over time. Eating becomes difficult, then painful, and in some cases, impossible. While there is no known cause or cure, treatments include botox injections, balloon dilation of the LES, dietary changes, and in extreme cases, an esophagectomy.