A disorder characterized by persistent or recurrent symptoms other than pain that are mediated by the autonomic nervous system (ANS) and not a part of a general medical condition. Symptoms may involve various systems or organs, including palpitations (cardiovascular), hyperventilation (respiratory), vomiting (gastrointestinal), urinary frequency (urogenital), or flushing (dermal). In earlier dsm classifications (dsm-i, dsm-ii, and dsm-iii), such symptoms were considered conversion symptoms, psychosomatic symptoms, or psychophysiological disorders.