I always thought my body could do anything. At 28, I would routinely run four miles at a stretch. At 32, I gave birth to my first child. Maybe that’s why when a deliveryman showed up one day about six years ago with the new sliding patio doors I’d ordered, I thought I could surely help lug them inside.
Bad idea. A few hours later, I felt an extreme tightening in my lower back. During the next couple of weeks, the pain worsened, depending on my activity. My butt and thighs ached after I pushed my 7-month-old daughter in her stroller. And my entire left leg — from my thigh to big toe — burned whenever I tried to close those new patio doors. I finally saw a doctor, who recommended physical therapy. Although I was pretty fit and only in my early 30s, it took me five months to recover.
Then one night about two years later, my husband and I got into an argument. I stormed out of the house, slamming the front door behind me. In that instant, the pain returned and then continued to pop up in new places during the next six months. I had trouble turning my head, and my left arm became weak. Later, I developed a fiery sensation in the middle of my back, beneath my left shoulder blade.
Many doctor visits, two diagnoses of herniated disks and several more months of physical therapy later, my symptoms still plagued me. I could barely push a grocery cart without triggering a deep ache through my left leg. Even sleep didn’t come easily: Rolling over felt like a knife slicing across my back. Worst of all, I could no longer hold my two toddlers on my lap without throbbing pain.
Now I have a name for my condition: chronic pain, which is defined as discomfort that persists for three to six months or longer. Yet I still don’t have a satisfying explanation for it. When the results of magnetic resonance imaging scans of my back and neck indicated that I never actually had herniated disks, I was surprised, but my doctors weren’t: MRI findings don’t often reveal the cause of back pain. My neurological exams, which tested reflexes and strength to determine whether spinal nerves might be irritated or compressed, also turned up nothing.
In my two-year odyssey to find a cause and a cure, I’ve learned that chronic pain frustrates doctors and patients alike. Because pain itself is invisible, and it’s often impossible to pinpoint a trigger, young, healthy patients are frequently dismissed, especially if they are female.
“Doctors don’t assess pain as well in women,” says Carmen R. Green, M.D., director of pain management research at the University of Michigan at Ann Arbor. “They may think, Can a mother really have pain if she’s able to take care of her kids?”
That attitude aside, one reason many doctors have trouble diagnosing and treating pain is that until recently, medical experts viewed pain as merely a symptom. Today, researchers know that chronic pain itself is a disease of the central nervous system because, as happened to me, it can persist indefinitely after an initial injury has healed. Sometimes there is no specific injury to blame, as in the case of fibromyalgia, the baffling disease marked by muscle pain, tenderness and fatigue.
Over time, prolonged discomfort can permanently damage your nervous system, diminishing your body’s ability to ease pain, so you experience it more intensely. According to one researcher, if you can’t treat the ache within a short window, it’s more likely to persist. “Central nervous system changes peak at three weeks of pain, and then they may become irreversible,” says Clifford Woolf, M.D., professor of anesthesia research at Harvard Medical School in Boston.
Unfortunately, most doctors and patients aren’t aware of how urgently treatment is needed. One survey conducted by the American Chronic Pain Association in Rocklin, California, found that 72 percent of people with chronic pain have lived with it for more than three years, and a third have dealt with discomfort for longer than a decade. Chronic pain interferes with a sufferer’s life, straining relationships, deep-sixing careers and leading to depression, even suicide. Thankfully, new discoveries in research are finally giving doctors a better understanding of how pain becomes persistent — and the best ways to ease suffering.
The path to permanence
One of the mysteries experts are trying to unravel is why some people suffer indefinitely. I didn’t have a single pain-free day for a solid year. Studies show that 5 to 10 percent of people who are injured develop chronic pain. The nature and extent of your injury, of course, play major roles in whether your pain becomes long-term (nerve damage, for instance, poses that risk), but your odds are even greater if you have a genetic predisposition. “When a nerve is damaged, more than 1,000 genes are changed, but some people are born more susceptible to those changes than others, thus making them more likely to suffer,” Dr. Woolf says.
Simply being a woman can leave you more vulnerable. About 60 percent of the 50 million chronic-pain sufferers in the United States are female, partly because sex hormones make some women more sensitive to discomfort than others. If you happen to be sick or hurt at the time of your injury, the chances of your pain lingering may be higher still. Animal studies suggest illness or prior injury can trigger certain immune cells to release pain-amplifying chemicals called proinflammatory cytokines, says Joyce DeLeo, Ph.D., director of the Neuroscience Center at Dartmouth College in Hanover, New Hampshire.
To compare ordinary acute pain to chronic pain, think about the last time you stubbed your toe. The affected nerves sent an electrical message to your spinal cord, which in turn told your brain to feel pain. Your blood pressure increased, and your heart raced. The pain likely lasted for a few days; it was your body’s way of telling you to rest your toe so it could heal.
But an intense injury or illness can cause pain pathways to become overly sensitive, much like a broken car alarm that won’t quit blaring. Your injured tissue may produce inflammatory chemicals, which promote healing but can also sensitize nerve cells bodywide. (This reaction partly explains why taking a warm shower when you have a sunburn is especially painful.) In addition, the brain itself can become overly sensitive. An injury leads to a burst of activity in nerve cells, which bombard the spinal cord with electrical signals, amplifying pain messages to the brain.
The result of hypersensitive nerve cells, whether in the body or brain, is the same: You experience pain all the time, for no apparent reason. Uninjured body parts suddenly become more delicate, and your threshold for pain drops, so things that wouldn’t normally make you flinch (such as a hug or a cool breeze) are uncomfortable. Something that’s always painful — like getting a shot — causes more pain, and longer than usual. All the while, Dr. Woolf says, “there may be no detectable physical abnormality.”
Pain and stress: A vicious cycle
Along with the physical agony, pain can lead to depression. I worry about letting my limitations affect my kids, but it sometimes breaks my heart that I can’t pick them up or even push them in a swing or teach them how to play tennis. Studies show that between 30 and 54 percent of all chronic-pain patients have been diagnosed with clinical depression, and more than half of the rest suffer from one or more depressive symptoms which include fatigue, changes in sleep habits, loss of appetite and overeating. And while pain often brings on depression, research also shows that people who are depressed are more likely to experience an onset of chronic pain.
It’s not surprising that the two conditions, both characterized by feelings of helplessness and sadness, go hand in hand. But there’s also a biological explanation. The same brain chemicals — serotonin and norepinephrine — that are lower than normal in depressed people also ebb in people with chronic pain, says Carol A. Warfield, M.D., chief of anesthesia, critical care and pain medicine at Beth Israel Deaconess Medical Center in Boston. “They may be depleted when pain becomes chronic,” she says. That’s why certain antidepressants, which raise levels of these chemicals, are now used to treat chronic pain.
Of course, not everyone with chronic pain becomes depressed. “There are people who adjust well to the limitations imposed by their pain,” says Joshua Wootton, Ph.D., director of pain psychology at the Arnold Pain Management Center at Beth Israel Deaconess Medical Center. But for those coping with both depression and pain, some new findings offer hope. Alex Zautra, Ph.D., codirector of the Resilience Solutions Group at Arizona State University at Tempe, who studies what makes some chronic-pain sufferers more resilient than others, says people who maintain their usual activities and focus on positive emotions do best. “These people have the same amount of pain but suffer less,” he says.
Being active can also prevent pain from becoming disabling. Many people restrict their regular pursuits such as exercise because they’re afraid of worsening their symptoms, or their primary care doctors advise rest. But sitting on the sidelines only prolongs pain. If you’re inactive for a long period of time, you lose endurance, flexibility and strength. The result: additional pain due to out-of-shape muscles. “It’s important to keep using your muscles, even if some activities hurt,” says Dennis Turk, Ph.D., John and Emma Bonica professor of anesthesiology and pain research at the University of Washington at Seattle. You can feel some pain — the “good” kind that comes with a challenging but not overly taxing workout — without causing injury. “Once your doctor has ruled out a significant problem, like a fracture, you have to begin slowly building yourself up.”
To help people deal with their fears of reinjury, some experts are using a technique called exposure. “We ask people to identify the activities they’re afraid of, and we teach them to confront their fears,” Turk says. “We start at a lower level of activity and build up 10 to 20 percent each day. Patients see that they can do more, and they acquire a sense of mastery.” The technique doesn’t cure pain — but it can help reduce it.
The brain on pain
Finding ways to alleviate pain quickly is important not only for preventing permanent changes in the central nervous system but also because chronic back pain may actually shrink areas of the brain that regulate memory and information processing, according to a study in The Journal of Neuroscience. Researchers using MRI scans found that patients who had chronic back pain for at least two years had 5 to 11 percent less gray matter in the brain’s prefrontal cortex and thalamus than people without back problems. The decrease is equivalent to the gray matter volume lost in 10 to 20 years of aging. A possible explanation: Nerve cells are dying in these brain regions. “We think the suffering causes the loss of gray matter, because we showed that patients who were in chronic pain for a long period of time were worse off,” explains A. Vania Apkarian, Ph.D., professor of physiology at the Feinberg School of Medicine at Northwestern University in Chicago.
What’s more, people in pain may also have trouble with emotional decision making because the prefrontal cortex — which is also responsible for sizing up emotional situations—is affected. In a separate study published in Pain, Apkarian examined chronic-back-pain patients who were each given a gambling card game to play. (Gambling is considered an emotional task.) They performed poorly compared with healthy participants. The explanation? “Suffering keeps people in an emotionally overwhelmed state, so they’re less able to address other emotional demands,” Apkarian says. Based on his findings, he is starting a clinical trial this year to test a new chronic-back-pain drug that targets the brain chemistry involved in the areas of degeneration. Although the drug might not be able to replace lost brain cells, it may help decrease suffering.
Searching for a cure
The array of conventional and complementary treatments for chronic pain have been shown to have varying levels of success among patients. That makes research such as Apkarian’s critical to finding targeted options for patients — a trend that’s already starting to take hold. For example, because recent research indicates that people who suffer from chronic lower back pain for which no cause can be found and fibromyalgia have hypersensitive central nervous systems, doctors are prescribing medications, like certain tricyclic antidepressants (such as amitriptyline and imipramine), to address that sensitivity, according to Daniel J. Clauw, M.D., director of the Chronic Pain and Fatigue Research Center at the University of Michigan at Ann Arbor.
Other studies are showing that when it comes to stopping pain, your mind may be as powerful as any drug. Recent brain-imaging research reveals that focusing on the discomfort enhances the pain signal that goes to your brain. But if you’re distracted, the signal will be dampened.
For instance, if a friend criticizes a patient about her discomfort instead of trying to take her mind off things, the pain could get worse rather than better. “Attention is like a spotlight,” Arizona State’s Zautra says. “When you shine it on something else, the pain darkens and you won’t suffer as much.” Your mood also plays a role in your experience of pain. “When we changed people’s emotional state — putting them in a bad mood or making them anxious by showing an unpleasant video — their pain bothered them more,” says M. Catherine Bushnell, M.D., director of the McGill Centre for Research on Pain at McGill University in Montreal.
As I write this, now nearly six years after my first injury, I’m not in pain. My symptoms have improved over time and through physical therapy to the point that there are days when I actually forget I have a back problem — that is, until I push, pull or lift something heavy. Still,
I refuse to let fear control my every movement. I can painlessly open and close my front door (slowly and avoiding twisting), change diapers and push a cart half-full of groceries. And when the pain returns, as it does now and then, I simply try to ignore it and move on. My brain seems to appreciate the distraction, and often relief soon follows. I know I may never have a completely pain-free life, but I have a new appreciation for what my body can do.