New directions in the understanding and management of pain

Control of pain and the suffering that it causes still eludes us. Despite impressive progress in the prevention and cure of disease and in care of the trauma victim, pain is still a frontier in medical research. It accompanies surgery, various diagnostic procedures and dental care as well as acute injury and disease. For a significant number of patients it persists after injury or illness into a chronic state. Chronic pain is recognized to be the most frequent cause of disability in the United States and many industrialized nations today, and is a major cost to society in both work hours lost and medical expenses. In addition to its social importance, pain is an intimate cause of personal concern for every human being throughout life. The progress, or lack of progress, achieved by medical research in pain control is of interest to us all. Pain disorders may be usefully classified in two categories: acute and chronic. The etiology, physiopathology, symptomatology, diagnosis and therapy of these two types of pain are quite different and require separate consideration. Acute pain is that which arises from an acute injury or disease process and persists only as long as the tissue pathology itself. If acute pain problems are not effectively treated, they may progress to chronic states. Chronic pain is that: (1) associated with chronic tissue pathology; or (2) which persists beyond the normal healing period for an acute injury or disease. There are unique challenges for health care providers associated with each of these two categories of problems, and failure to distinguish between these types of pain has led to a widespread, ongoing mismanagement of patients that can be prevented if strong efforts are made to better educate health care professionals about pain and its therapy. This paper presents an overview of current understanding about the nature of pain and its management. The physiology and psychology of pain are reviewed against a background of the concepts and information taught 25 years ago. Some common acute and chronic pain problems are reviewed and discussed. Finally, several new directions in pain control are described.