[Concept of functional somatic syndromes].

"Functional somatic syndromes" is one of the new terminologies in the medicine. However most of the primary-care physicians have already noticed the existence of the patient appeal their physical symptoms which is medically unexplained for a long time. On the other hand, the psychiatrists looked same physical symptoms as a symbolic representation of the patients' psychological conflicts, somatoform disorders. This new terminology "functional somatic syndromes" intends to integrate those two dimensions and to understand the patient as a whole person. In this special issue, we show the multi-dimensional aspects of "functional somatic syndromes" and intend to serve the clue to understand the patients with symptoms to all primary-care physicians in Japan.