Tags: Disease.
Achalasia (/eɪkəˈleɪʒə/; a- and -chalasia no relaxation) is a failure of smooth muscle fibers to relax which can cause a sphincter to remain closed and fail to open when needed. Without a modifier achalasia usually refers to achalasia of the esophagus which is also called esophageal achalasia achalasia cardiae cardiospasm and esophageal aperistalsis.
