1847, "pertaining to the relation between mind and body," from Greek psykhe- "mind" (see psyche) + somatikos, from soma (genitive somatos) "body" (see somato-). Applied from 1938 to physical disorders with psychological causes. Etymologically it could as easily apply to emotional disorders with physical causes, but it is rarely used as such.
psychosomatic psy·cho·so·mat·ic (sī'kō-sō-māt'ĭk)
Of or relating to a disorder having physical symptoms but originating from mental or emotional causes.
Relating to or concerned with the influence of the mind on the body, especially with respect to disease.
A descriptive term for the relationship between the mind and body.
Note: “Psychosomatic” disorders have definite physical symptoms but are thought to be caused by emotional or psychological factors. Anorexia nervosa is an example of a psychosomatic illness.