Most people would agree that pain is an unpleasant sensation, often referring to physical pain like carpal tunnel syndrome, gunshot wound, or a sunburn. Sometimes these types of pain can be acute or chronic pain.
But pain is not always an indication that there is tissue damage, disease, or abnormalities present in your body, as some clinicians might say. After all, there are many people who have shoulder “abnormalities” or leg length discrepancies with no pain and function normally.
Some clinicians might say that it is your body sending “pain signals” to your brain, but how could that be possible for those who have phantom limb pain where they do not even have that body part?
So pain is much more complex than just the degree of tissue damage or there is something wrong with your posture. Currently, the body of scientific literature about pain indicates our pain experience is influenced by a combination of biological, psychological, and sociological factors (biopsychosocial). Each factor does not function by itself in its own bubble; they are constantly interacting like a mixture in a baking recipe.
For example, you are working at a highly stressful desk job (e.g. journalism, criminal law) and you have been sitting for three hours, you may experience low back pain from being in the position for so long.
However, you might be able to sit and play “World of Warcraft” or binge-watch “The Queen’s Gambit” for six hours with minimal or no pain because the activity is enjoyable to you and may be a stress reliever. Even though you are still sitting for a long time, your environment and perception play a big role in whether you will experience low back pain or not.
Pain exists not “just in your brain.” Sensory receptors on your skin and hormones and immune cells flowing through your bloodstream are constantly detecting potential danger and communicating with your nervous system.
If there’s a sudden change in your environment (e.g. touching hot water from a faucet, a bone fracture from a fall), these sensors galvanize your brain into action, igniting inflammatory systems and increasing blood flow to the (potential) site of injury or pain.
Types of pain
Pain is generally boxed into acute pain or chronic pain. Acute pain is short-term, lasting less than three months, while chronic pain lasts more than three months. Subacute pain hovers in a limbo of six weeks to three months.
Sometimes pain is categorized based on location, such as neurological, visceral, or musculoskeletal. While these types of pain are often diagnosed and treated differently, emerging research indicates that treatment and management should have a common ground based on the biopsychosocial model of pain, such as giving reassurance to patients, listening to the patients’ narrative, and treating the person not just the body part.
Acute vs. chronic pain treatment
Physicians and most healthcare professionals treat pain differently, depending on the duration, location, and the nature of the pain. While acute and chronic pain share many of the same neural, immunal, and endocrine pathways that give us pain, treatment and management can be quite difficult because of the individual differences.
“I don’t, as a general rule, treat acute and chronic pain differently, assuming my rule-outs are all negative,” said registered massage therapist Rob Haddow, who runs a clinic in Oakville, Ontario. “Whether a person has had an issue for a day, or a year, it’s still a real thing for them.”
While Haddow still considers the differences among patient cases — from an ankle sprain from gymnastics to chronic low back pain of an office worker — he still maintains the foundation of pain science as part of his communication to patients.
“I’ll still be pulling from the same pool of evidence I use to inform my practice, I’ll still be conscious of the explanations I use, I’ll still endeavor to offer uninterrupted listening, and following that, exploratory troubleshooting,” he said.
Occupational therapist Linda Crawford, who practices at Brave Therapy in Denver, Colorado, has a slightly different perspective about acute pain and chronic pain treatment because of each person’s individual differences.
“I would answer yes…and no,” she said. “A person with acute pain and a person with chronic pain may have similar or very different needs. We should be looking for those differences and adjusting any type of therapy or support to meet the individual person’s needs. I think it’s important to give the person in pain (acute or chronic) permission to teach us about what they need, rather than us always teaching them what we think they need.”
Crawford emphasized that whether a patient has acute or chronic pain, clinicians should do their best to “empower” them to improve their lived experience of pain.
“[The] most important is to encourage an understanding and belief in their own resilience and ability to self-manage and self-direct their own process of recovery,” she said. “This means we must believe it. too. Instead of being prescribers and directors, we become co-creators with the people we work with in helping them change their lived pain experience. This means we offer guidance and facilitation, listen more than we talk, and use words that build confidence rather than fear.”
Instead of focusing on the “best” treatment, scientific evidence indicates that having a variety of treatment options that best fit a patient’s specific condition would be ideal.
“We may use a few different specific treatment methods with each person, but every treatment method should be presented within the context of a therapeutic relationship that is dedicated to co-creation of the best treatment plan, with the goal of helping the person self-manage and self-live their own best lives,” Crawford said.
Medications and other treatments
Medications may help alleviate pain symptoms, particularly acute pain, but long-term reliance may lead to addiction and other negative side effects. Some of these include opioids, which target the brain and the spinal to stimulate analgesic effects, and non-opioid NSAIDS (nonsteroidal anti-inflammatory drugs) that target the inflammation in the affected tissues.
“The most common treatments for acute and chronic pain that the public are aware of, and commonly directed to, are passive treatments for physical symptoms, or cognitive behavioral treatments for the emotional symptoms,” Crawford said. “Physical treatments for pain symptoms may include the use of drugs, steroid or other nerve block injections, ultrasound, TENS units, deep tissue massage, adjustments, acupuncture, or surgery. Cognitive behavioral treatments attempt to help a person to change their thoughts to change their pain.”
Despite decades of studies and the gradual increase of understanding how pain works, Crawford said that clinicians have used these methods for many years yet the percentage of patients going from acute to chronic pain continues to rise with the overuse of opioid medications.
“We have evidence that ‘doing with’ instead of ‘doing to’ practices are more effective,” Crawford said. “We have evidence that validating a person’s lived experience, encouraging self-efficacy, and facilitating self-compassion can significantly improve their pain experience.
“And we have evidence that the more a person understands their pain experience, and all the complicated sensory, emotional, contextual, social, and cognitive factors that influence that experience, the better able they are to live their best lives with less pain.”
“Some say it is a reminder that they are broken, that their spine is ‘out’ or that their disc is ‘slipped’ (note to self: discs never slip. Ever). Others say it is punishment for their sins or a test of their faithfulness.
“Some scientists say pain is a particular pattern of brain activity; dodgy motivational talks might call pain ‘weakness leaving the body’ or profess ‘No pain? No gain!’” ~ Prof. Lorimer Moseley
So what is pain exactly?
Since most types of pain are difficult to treat, you likely respond to a treatment quite differently than someone else. Perhaps a better way to understand pain is to explore its roots, including the current and past understanding of pain.
Pain exists with or without injury
Among scientists who study pain, pain is no longer thought of as just the degree of tissue damage, “poor” posture, or “faulty” biomechanics. Instead, it is a complex and protective system where our brain gathers and processes a ton of information, including how safe we are. Thus, there is no such thing as a “pain receptor” or pain nerve fibers.
However, we do have specialized nerves and various sensory organs in the skin that detects changes in our environment, such as temperature, pressure, and infections. One of these is called “nociceptors,” which sends signals to the spinal cord and the brain.
These signals are not pain; instead, the brain and spinal cord process these signals and may or may not generate the pain experience.
Pain science history: Descartes to Melzack
Pain as we understand it today comes from nearly five centuries of research and wonder. Although various cultures throughout history have their own beliefs and narratives about pain, science and humanities have revealed more about how it works and how it could be treated. They are not perfect, but history has shown that there has been a gradual progress in understanding how pain works—from the mythical beliefs about spirits and humors to purely biology and the eventual inclusion of psychosocial factors that gives us the pain experience.
Gate control theory of pain
While there have been many theories about pain since the early 19th century and each theory has gradually improved in explanation and understanding, the major breakthrough in pain research is the gate control theory of pain. Developed by Dr. Ronald Melzack and Dr. Patrick Wall in the early 1960s, the gate control theory of pain states that non-painful stimulus, usually from the peripheral nerves, can close the “gate” of the neurons in the spinal cord that relay messages to the brain.
Such stimulus overrides a painful stimulus, which is one explanation why you instinctively rub a painful area when it hurts like stubbing your toe and having an achy lower back. Perhaps massage therapy works in a similar way to some people with chronic low back pain or hip pain.
Neuromatrix theory of pain
The neuromatrix theory of pain is an update of the gate control theory, where it shifts the focus away from the peripheral nerves and toward the spinal cord and the brain. It does not negate the previous theory; it expands its explanation.
Melzack describes the neuromatrix as a network of neurons in the brain that loops between the cerebral cortex, the thalamus, and the limbic system. This “loop” is different for everyone because we all have unique experiences, environments, social upbringings, and genetics, which create our personal neurosignature.
The neurosignature is the pattern of neural impulses that the neuromatrix produces. How we sense pain and respond to stress depend on the complex interaction among different factors, including our biology, how we feel, what we think and believe, and our environment.
Like most scientific theories, new ideas will eventually replace existing ones. Just like how the neuromatrix theory replaced the gate control theory, the enactive approach to pain is an attempt to further expand on the biopsychosocial model of pain by integrating the teachings of philosopher Shaun Gallagher, who developed the “4E” as a novel way to understand the human mind.
Dr. Peter Stilwell and Dr. Katherine Harman, who proposed the enactive approach to pain, described it as “the bigger picture” of pain where the biopsychosocial model of pain continues to “perpetuate dualistic and reductionist beliefs.”
Given the enormity and the ever-changing nature of pain science, it is not a surprise that many clinicians and schools are still behind in their practice and curriculum. After all, it takes an average of 17 years for research to be translated into mainstream medical education. (For the gate control theory, which was first published in medical journals in 1965, this novel idea at the time did not reach medical school textbooks until 1973.)
“I’d like to see [physicians] learning about the potential harm of misinformation in pain management, and some accountability served up to the treatment mills and rotating-door clinics making literally millions of dollars pedaling placebos and encouraging dependency,” Haddow said.
Crawford mentioned that changing the current healthcare culture from a “stop-it-fix-it” to a “care-for-co-creation” culture will be challenging and will need many people—clinicians and the public—to support the movement.
“These ‘newer’ treatment methods are better, but difficult to market against the promise of quick fixes or cures from some of the more commonly known treatments,” Crawford said. “Getting better takes time. That’s true for people in pain, and for those who work with people in pain.”