Conversion syndrome describes a condition in which physical symptoms arise for which there is no clear explanation. The term stems from the 19th century European conception of hysteria, which itself can be traced back to Ancient Egyptian papyri from the 16th century BC. Psychiatrists now separate out conversion disorder, in which the complaints are neurologic, from similar conditions in which the complaints can be about such things as pain.
Patients with conversion and hysteria led Sigmund Freud to his theories on the unconscious and the talking cure, and the same patient population intrigued such physicians as Pierre Janet, J. M. Charcot, and Josef Breuer. Freud theorized that unacceptable emotions led to psychological conflict that was then converted into physical symptoms. Much recent work has been done to identify the underlying causes of the somatoform disorders as well as to better understand why conversion and hysteria appear more commonly in women. Current theoreticians tend to believe that there is no single reason that people tend to somatize, or use their bodies to express emotional issues. Instead, the emphasis tends to be on the individual understanding of the patient as well as on a variety of therapeutic techniques.