Chronic pain is a silent epidemic of immense proportion. It has been estimated that more than 70 million Americans live with chronic pain, and the impact on the individual, the family, the workplace and society at large is staggering. A recent survey of 805 people with moderate to severe chronic pain found that:

56 percent have been suffering for more than 5 years.

Greater than 50 percent report that pain negatively affects their abilities to sleep, walk or exercise, enjoy activities or socialize.

47 percent have changed doctors once and 22 percent have changed doctors three or more times in the effort to find relief.

Fewer than one-quarter have seen a pain specialist and only 45 percent take prescription drugs for pain (16 percent use opioid, or narcotic, drugs).

Both acute and chronic pain continue to be undertreated. The degree of undertreatment can be measured when there is a medical consensus about the nature of optimal therapy, as there is for the treatment of cancer pain and acute pain. Every recent survey of patients with these problems concludes that pain is poorly recognized and poorly assessed, and is treated inadequately in a large proportion of patients. Unfortunately, medical professionals and the systems of care in which they work (like hospitals and nursing homes) often lack the attentiveness and skills necessary to deal with the complex needs of patients living with different kinds of chronic pain.

Accountability. This situation is disheartening, but there is reason to hope that progress is being made because of new systems of accountability, evolving medical disciplines, scientific research and novel therapeutics.

In a momentous decision, the Joint Commission on the Accreditation of Healthcare Organizations, the body that accredits hospitals and other medical facilities, has adopted new standards for pain management that will be used to measure hospital quality. The new standards require institutions to (1) recognize the individual's right to appropriate pain care, (2) assess pain on a regular basis, (3) establish policies and procedures that support good pain management, (4) educate patients and families about effective pain management, (5) address the need for symptom control on discharge from the institution, and (6) incorporate pain management into institutional performance-improvement programs.

One of the important ways that institutions will become accountable is by measuring pain on a regular basis. This is the goal of the "Fifth Vital Sign" concept of the American Pain Society. Pain should be regularly measured in every inpatient, just like pulse and blood pressure. Many hospitals are considering this change, and the Veterans Administration has made this a cornerstone of a new national program to improve pain management.

Evolving Disciplines. Effective pain management is a fundamental principle of palliative care, and the advent of a vibrant national movement to bring palliative care to every setting will certainly benefit those with uncontrolled pain. Palliative care is an approach that focuses on patients with life-threatening illnesses and their families. It emphasizes good communication; comprehensive, quality-of-life-oriented care throughout the disease; and intensive therapy to assure comfort and support as death approaches. Specialists in palliative care are trying to integrate these principles into routine disease management and also establish palliative care as a specialty in medicine and other disciplines.

Research. There is a deepening understanding of the pathologic changes that distinguish "normal" pain accompanying acute tissue injury from the many types of chronic pain. Chronic pain is actually many different disordersÑarthritis does not produce pain in the same way that headache does. Indeed, recent studies indicate that there may be different mechanisms for pains that arise from different tissues or have different qualities. In the future, different drugs may be selected for aching limb pain, cramping intestinal pain and burning skin pain.

New research is also identifying important differences in the way various patient groups react to drugs. Some studies, for example, indicate that women, and not men, respond to opioids that react with the so-called kappa opioid receptor. Others have shown that some people do not metabolize codeine and may not experience pain relief when given the drug. The new field of pharmacogenomics is developing methods for discovering these key genetic differences that may influence the way patients respond to pain-relieving drugs.

Novel Therapies. New drugs for pain are on the horizon. As neurobiologists uncover the physiology and pharmacology of pathologic pain, drugs are being created that influence these processes. In the near future, physicians may be able to administer new types of anti-inflammatory drugs and new chemical entities that may modulate the causes of pain following injury to nerve tissue. Opioids are being used more and more for chronic pain, and physicians are learning to administer these drugs safely and effectively. An important study recently showed that a large increase in the medical use of opioid drugs between 1990 and 1996 was not accompanied by evidence of increased drug abuse.

For carefully selected patients, opioids and other drugs can be delivered into the spine. And in the near future, other novel routes of drug administration are likely to become available.

Dr. Portenoy is chairman, Department of Pain Medicine and Palliative Care, at Beth Israel Medical Center, and professor of neurology at Albert Einstein College of Medicine, both in New York City.