Pain is an unpleasent sensory and emotional experience associated with actual or potential tissue damage. Behavioral manifestation of pain, distress, and suffering have been characterized as pain behaviors. Pain behavior is the way individuals think, feel, and act in relation to their pain status. Pain behaviors are either adaptive or pathological, as when the pain behavior is disproportionate to the objective pathology. It's reported that when pain behavior exists in patients with pain, a psychiatric disorder might to increase pain. The relation between psychological factors and pain behavior is investigated in several studies.