Recent progress in understanding the mechanisms of pain and itch
Sensory Plasticity Laboratory, Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital and Harvard Medical School, 75 Francis Street, boston, MA 02115, USA
Chronic pain is a major health problem world-wide. According to a recent report in the New England Journal of Medicine , the prevalence of pain in the United States is striking: more than 116 million Americans have pain that persist for weeks to years. Chronic pain is characterized as inflammatory pain, cancer pain, and neuropathic pain, and can result from such conditions as arthritis, cancer, diabetes, low back injury, surgery, viral infection, spinal cord injury, and stroke. It is estimated that the total financial cost of this epidemic is $560-635 billion per year in the USA. It is worthy of note that the annual USA expenditure on pain (including direct medical costs and lost wages) is higher than that on cancer, heart disease, and diabetes combined. Despite the enormous costs, the treatments covered by these expenditures can only partially alleviate Americans’suffering. Comparatively, pain management in developing countries is far less than sufficient .