Douglas Harper's Etymology Dictionary
1909 in biology (Rignano); 1920 in psychology; from somato- "body" + -ization.
Wiktionary
n. (context medicine English) The generation of physical symptoms of a psychiatric condition such as anxiety
Wikipedia
Somatization is a tendency to experience and communicate psychological distress in the form of somatic symptoms and to seek medical help for them. More commonly expressed, it is the generation of physical symptoms of a psychiatric condition such as anxiety. The term somatization was introduced by Wilhelm Stekel in 1924.
Somatization is a worldwide phenomenon. A somatization spectrum can be identified, up to and including at one extreme somatization disorder.
Usage examples of "somatization".
These efforts, including repression, self-blame, self-injury, traumatic bonding, addictions, somatization (conversion of stress into physical symptoms), dissociation, multiple personalities, and other defenses, are unconscious and, unfortunately, they can create almost as many problems as they solve.