Pain—it’s something we’ve all experienced. From our first skinned knee to the headaches, back pain and creaky joints as we age, pain is something we encounter many times. Most pain is acute and goes away quickly. But in some cases, when pain develops slowly or persists for months or even years, then it’s called chronic pain, and it can be tricky to treat.
Chronic pain is a huge problem. Over 115 million people nationwide—about 1 in 3 Americans—suffer from some kind of long-term pain. It’s the leading reason that people miss work.
NIH-funded scientists are working to better understand and treat chronic pain. They’re uncovering the intricate pathways that lead to long-term pain. And they’re looking for approaches beyond medication that might help you control your pain.
Chronic pain differs in many ways from acute pain. Acute pain is part of the body’s response to an injury or short-term illness. Acute pain can help prevent more serious injury. For instance, it can make you quickly pull your finger away from a hot stove or keep your weight off a broken ankle. The causes of acute pain can usually be diagnosed and treated, and the pain eventually ends.
But the causes of chronic pain aren’t always clear. “It’s a complex problem that involves more than just the physical aspects of where the hurt seems to be,” says Dr. John Killen, deputy director of NIH’s National Center for Complementary and Alternative Medicine. “There’s a lot of accumulating scientific evidence that chronic pain is partly a problem of how the brain processes pain.”
Chronic pain can come in many forms, and it accompanies several conditions including low-back pain, arthritis, cancer, migraine, fibromyalgia, endometriosis and inflammatory bowel disease. These persistent pains can severely limit your ability to move around and perform day-to-day tasks. Chronic pain can lead to depression and anxiety. It’s hard to look on the bright side when pain just won’t go away. Some experts say that chronic pain is a disease itself.
The complexities of chronic pain can make it difficult to treat. Many of today’s medications for chronic pain target inflammation. These drugs include aspirin, ibuprofen and COX-2 inhibitors. But if taken at high doses for a long time, these drugs can irritate your stomach and digestive system and possibly harm your kidneys. And they don’t work for everyone.
“With hard-to-treat pain, the opioids are also used, sometimes in combination with the other drugs,” says Dr. Raymond Dionne, who oversees some of NIH’s clinical pain research. Opioids include prescription painkillers such as codeine and morphine and brand-name drugs such as Vicodin, Oxycontin and Percocet. Opioids affect the processes by which the brain perceives pain. If used improperly, though, opioids can be addictive, and increasingly high doses may be needed to keep pain in check.
“As with all drugs, you have to find a balance between effectiveness and side effects,” says Dionne. He and other researchers have studied potential new pain medications to learn more about how they work in the body. But for the most part, pain medications are similar to those used 5 or more decades ago. That’s why some researchers are looking for approaches beyond medications.
“One thing we know is that currently available drug therapies don’t provide all the answers. Many people find that medications don’t fully relieve their chronic pain, and they can experience unpleasant side effects,” Killen says. “Evidence on a number of fronts, for several conditions, suggests that mind and body approaches can be helpful additions to conventional medicine for managing chronic pain.”
Research has shown that patients with chronic low-back pain might benefit from acupuncture, massage therapy, yoga or cognitive-behavioral therapy (a type of talk therapy).
NIH-funded scientists have also found that people with fibromyalgia pain might find relief through tai chi. This mind-body technique combines meditation, slow movements, deep breathing and relaxation.
But how much these approaches truly help is still an open question. Studies of pain relief can be difficult to interpret. Researchers must rely on patients to complete questionnaires and rate their own levels of pain.
One puzzler is that the exposure to the exact same pain-causing thing, or stimulus, can lead to completely different responses in different people. For example, when an identical heat stimulus is applied to different people’s arms, one may report feeling uncomfortable, while another might say that the pain is extreme.
“How do we account for these differences? We’ve now learned that genes play a role,” says Dr. Sean Mackey, who heads Stanford University’s neuroscience and pain lab. “Some differences involve our personality and mood states, including anxiety.”
Mackey and his team are using brain scans to gain insights into how we process and feel pain. One study found that a painful stimulus can activate different brain regions in people who are anxious than in those who are fearful of pain.
In another study, volunteers were taught strategies that could turn on specific brain regions. One technique involved mentally changing the meaning of the pain and thinking about it in a non-threatening way.
“We found that with repeated training, people can learn how to build up this brain area, almost like a muscle, and make its activity much stronger,” says Mackey. “That led to a significant improvement overall in their pain perception.” The researchers also found that different types of mental strategies, such as distraction, engaged different brain regions.
Another study found that intense feelings of passionate love can provide surprisingly effective pain relief. “It turns out that the areas of the brain activated by intense love are the same areas that drugs use to reduce pain,” says Mackay.
“We can’t write a prescription for patients to go home and have a passionate love affair,” says Mackey. “But we can suggest that you go out and do things that are rewarding, that are emotionally meaningful. Go for a walk on a moonlit beach. Go listen to some music you never listened to before. Do something that’s novel and exciting.”
That’s a prescription that should be painless to try.
