as we will hear from laurie klein, chronic pain is a disease in its own right. as these arguments make clear, this is an enormous public health problem. 100 million americans as you pointed out suffer from pain every year, and it is the most common reason people seek medical attention. there are two kinds of chronic pain, inflammatory and neuropathic pain, inflammatory, receptive pain is damage to soft tissue and it shows the adaptive role of pain perfectly, it is designed to move the injured part of the body away from the damaging stimulus, so as to prevent further damage from occurring, and to allow the reparative processes to take place. but sometimes sort of a hypersensitivity develops with -- as a result of the inflammatory process so that relatively noxious stimulus like just touching the hand feels painful to the person. inflammatory pain is due to damage of soft tissue, but neuropathic pain involves in addition to soft tissue damage actually damage to the nerve fibers themselves. and this, not only involves hypersensitivity but spontaneous pain and burni