Concern about symptoms is a major reason for patients to seek medical help. Many of the somatic symptoms, such as pain of different location (back, head, muscles or joints, abdomen, chest), fatigue, dizziness, edema, dyspnea, insomnia, and numbness, often remain unexplained by identifiable disease even after extensive medical assessment. Terms such as somatization, somatoform disorders, abnormal illness behavior, functional symptom, and medically unexplained symptom (MUS) have been used to describe these symptoms. The term functional symptom assumes only a disturbance in...