Suffering and its relationship to pain.

Pain is a complex, multidimensional perception with affective as well as sensory features. In part, it is a somatically focused negative emotion resembling perceived threat. Suffering refers to a perceived threat to the integrity of the self, helplessness in the face of that threat, and exhaustion of psychosocial and personal resources for coping. The concepts of pain and suffering therefore share negative emotion as a common ground. Examination of the central physiological mechanisms underlying pain, negative emotional arousal, and stress helps clarify the physiological basis of suffering and the causal influences of persistent pain and other stressors. Central mechanisms involve both limbic processing of aversive stimulation and disturbance of the hypothalamo-pituitary-adreno-cortical axis with consequent biological disequilibrium. The palliative care specialist can address suffering proactively as well as reactively by treating potentially chronic pain and symptoms aggressively and promoting the psychosocial well-being of the patient at every opportunity.