One evening in 1992, Thomas Greenly kissed his wife and children good night and then went out to kill himself. With his loaded service revolver in hand, the retired police officer sat for hours at a local park, shaking and crying, trying to think of reasons not to end his life.

Ten years earlier he'd been attacked by seven men and thrown through a plate-glass door while responding to a domestic violence call. The incident left Greenly with several ruptured disks and ended his police career at the age of 29. It also left him with non-stop pain that felt like flames running up and down his spine.

His doctors certainly tried to put out that fire. He had four back surgeries, bone fusions, knee surgery, and physical therapy; he tried meditation, trigger point injections, biofeedback, electrical nerve stimulation, and a chronic pain clinic. None of the surgeries or therapies brought any lasting relief.

The only thing that worked was a daily dose of the drug hydrocodone. But he wasn't getting it: His doctors, concerned about the medical and legal risks of keeping him on a potentially addictive opiate, cut off his prescription. "They were afraid of addiction even though the pain was unbearable," Greenly recalls. "Long-term narcotic care…just wasn't done back then."

Without medication, Greenly couldn't work or sleep. He couldn't pick up his kids, make love to his wife, or sit down without searing pain. And if he couldn't get drugs to shut out his agony, he decided, he couldn't live anymore. "I had the gun in my hand, and I was going to shoot myself in the head," he says.

But love for his family kept Greenly from pulling the trigger. And when he got home, his wife had unexpected news.

While he was contemplating suicide, his wife had been watching a television special about Harvey Rose, a family physician who treated chronic pain patients. Right after she told her husband about the program, Greenly called Dr. Rose. "He told me I wasn't alone," Greenly says. "He told me he could help me."

That call changed Greenly's life. Dr. Rose conducted a history and exam and put him back on hydrocodone. "He was suicidal, he had documented injuries -- just the sort of patient that should be able to get the pain medication he needs," Dr. Rose says.

Physicians like Dr. Rose, armed with an impressive array of new therapies and drugs, novel approaches, and updated attitudes, are reshaping the battle against pain. Even the federal government is on board. Pain is now often called the "fifth vital sign," and doctors and nurses are being encouraged to assess and record pain levels just as they would blood pressure, pulse, temperature, and respiration rate. Meanwhile, pain control has developed into a specialty in and of itself. Experts now think persistent pain is not always a symptom of a condition. When a disordered sensation of pain is the primary problem, it may sometimes be a syndrome in its own right.

These developments can help physicians give chronic pain sufferers something few of them previously had: hope. They can also help patients like Thomas Greenly find relief long before things get desperate.

What exactly is chronic pain? Unlike acute pain, which has a protective function, it's pain that persists long after the original injury, causing suffering that lasts for weeks, months, and years.

But while definitions have been easy to come by, the mechanisms of pain have only come into focus over the last twenty years or so, thanks to recent discoveries in physiology and neurology. Only a few decades ago, pain was seen as a message that traveled from an injury to the brain just as a voice travels over a telephone wire. The concept was easy to grasp, and seems to be borne out by every stubbed toe. But it was terribly incomplete.

Pain is not a simple message, and the nerves that carry it are far from faithful messengers. The sharp pain of a stubbed toe does pass fairly directly from nerve fibers in the foot to the brain, but the dull throbbing and aching that follows -- or any long-lasting pain -- takes a completely different route.

As early as the 1960s, Canadian psychologist Ronald Melzack and British physiologist Patrick Wall proposed a radical new theory for chronic pain: Traveling on nerves called C fibers, sensory information passes through a "gate" in the spinal cord's posterior bundle of nerve fibers known as the dorsal horn, which can either amplify the signal, tone it down, or block it off completely. Subsequent studies determined that the dorsal horn may send a signal of pain without any input from the C fibers, which is why some people feel pain in missing limbs.

More recent research from Dr. Melzack and others indicated that the message could change drastically once again when it reached the brain. Thoughts, moods, memories, even cultural differences shape the perception of pain, says Allan Basbaum, a neurobiologist and chair of anatomy at the University of California at San Francisco. The brain's power to mold pain explains why soldiers in battle sometimes report only minor twinges from compound fractures, he says.

Acute pain, of course, has a valuable function: As the body's alarm system it sets limits, warning of danger and damage. But pain that outlives its function -- chronic pain -- can be as devastating as it is useless. If it hasn't resolved after three months, it may become an alarm stuck in the on position and screaming in a reverberating cascade of suffering.

Scientists don't understand exactly how that works, "but the nervous system does have a memory," says Richard Chapman, a professor of anesthesiology and director of the Pain Research Center at the University of Utah. "Neural traffic changes not only the function but also the structure of the nerves." Persistent pain may also leave a cellular memory that sensitizes the spinal cord, making ensuing pain worse. There's also increasing evidence that these physiological changes can make the body more vulnerable to illness.

Though explanations of chronic pain are still being teased out in the laboratory, the costs and scope of its impact are clear.

Consider these painful statistics: While exact numbers are elusive, an estimated 50 million Americans suffer from persistent pain. Out of every 10 of those with moderate to severe pain, four fail to get enough relief. What's more, up to 45 percent of the population will seek medical help for pain at some point in their lives.

The toll -- in personal and workplace costs -- is staggering. A 2003 study published in the Journal of the American Medical Association found that lost productivity as a result of pain cost U.S. employers more than $61 billion a year. If lost wages, disability, workers' compensation, and health-care expenses are factored in, the total costs of chronic pain cost billions more.

With the graying of America, these costs will likely increase. Part of it is due to good medicine: More people with chronic illnesses are living longer. Part is demographics: Baby boomers are aging, and though they expect a more active lifestyle than their parents had at the same age, they are encountering osteoarthritis, back pain, and other chronic ailments. However, few of today's pain patients are inclined to suffer quietly. They expect results.

Part II: Is pain undertreated?

-- Judith Horstmann is a northern California health reporter who has written for many health and medical publications. Jennifer Biddle is a research associate at Consumer Health Interactive. Part of this story was adapted from an article by Horstmann published in Hippocrates magazine.

References

First published February 27, 2007
Last updated June 26, 2008
Copyright © 2007 Consumer Health Interactive