Patients with "medically unexplained" bodily symptoms form a major group in
the medical care system. Diagnostic and therapeutic problems very often ar
ise, and the concept of "somatization" promotes a better understanding of t
his patient group. Important historical stages in the development toward a
modern diagnostic classification of somatoform disorders are outlined. A cr
itical comment on the diagnostic approaches according to DSM-IV and ICD-10
follows.