No identifiable medical condition causing the physical complaints: hypochondriasis refers to physical complaints without a clear cause, and partic ularly severe anxiety focused on the possibility of having a serious disease. Hypochondriasis shares many features with panic disorder and other anxiety disorders, and rates of comorbidity with such disorders (and mood disorders) are high. The essential problem in hypochondriasis is anxiety, but usually present to physician because of physical complaints. Another important feature of hypochondriasis is that reassurance from numerous doctors that the person is healthy has, at best, only a short-term positive effect. Often such persons will return to the same or other doctors on the assumption that the doctor missed something initially in ruling out medical reasons for the symptoms. Little is known about the prevalence of hypochondriasis in the general population. Approximately 3% of medical patients may meet criteria for hypochondriasis.