Is Chronic Pain Caused By Tissue Damage or Something Deeper and More Primal?
An estimated 20.4 percent of American adults have chronic pain…
… and 8 percent have high-impact chronic pain, according to a report from the CDC in 2016.
Chronic pain is one of the most common reasons why adults seek medical care, and…
…can lead to anxiety, depression, restrictions in mobility, and reduced quality of life.
Traditional medicine is strongly rooted in a biomedical model that assumes pain is the result of a localized injury but… advances in neuroscience paint a very different picture.
Understanding how pain works is your first step towards managing your current pain levels in order to improve your life.
The Cartesian Model of Pain — And Why It Has Been Replaced
The Cartesian Model of pain utilizes the concept of mind-body dualism which assumes that the mind and body are distinct and separate. Even though this model is over 350 years old, it is still regularly used to educate patients about why they are in pain.
Doctors use visual aids like x-ray or MRI images and medical replicas of the human spine, bones and tissues to illustrate how an isolated injury and localized damage are to blame for producing their pain. They often use harsh language like bulging, torn, or herniated to describe a patient’s pain. This process can actually cause additional harm — especially when aiming to help patients better understand the cause of pain.
Even though pain is often described using the Cartesian model throughout the medical community, researchers no longer think of chronic pain as stemming from tissue damage. Recent science now shows that pain is much more complex, involving our primal fight-or-flight responses and overstimulated nerves, as well as social, cultural, psychological, biological, and environmental factors. Advancements in neuroscience, brain imaging, cellular biology and immunology, have replaced this outdated model with a more complete picture.
How Does Pain Really Work?
If you break your wrist or twist your back, you feel pain in the area that is injured or damaged. However, pain is not actually coming from these areas. Instead, nerves that detect pressure, temperature, and chemical imbalances relay data back to the brain. Your brain then evaluates that information and decides whether or not you should feel pain.
While your back or leg may be broken or twisted, it is your actually brain that produces the pain. For example, if you stub your toe, nerve receptors near the injury send a message to the brain by releasing chemicals. Your brain interprets these chemical messages and decides if you should perceive your stubbed toe as painful. Your brain then sends a “pain message” back to your toe and you either feel the event as painful or not. This all happens very quickly.
The brain can usually pinpoint where in the body the pain is coming from accurately. However, in some cases, it doesn’t. For example, you may feel pain in your thighs, yet it is your lower back that requires your attention. Pain is simply our brain’s way of telling the body to take protective or defensive action in order to address what it perceives as a threatening issue.
This sophisticated chemical chain reaction can stimulate your “fight-or-flight” instincts. In times of significant danger, it is your body and mind’s way of keeping you safe. For example, during a mugging or a bear attack. However, if the fight-or-flight mode continues beyond the few seconds that a stubbed toe would typically last, these chemical messages are continually produced, and your brain translates the whole stubbed toe situation to mean you’re not safe. This causes your central nervous system to be over-stimulated and highly sensitized which leads to chronic pain.
Chronic Pain Is Multi-Dimensional
Pain is a universal experience, one that tends to be rather negative. But, since pain is highly subjective, there is no way to distinguish one person’s experience from the next. As stated in this review, many people report pain in the absence of any physical tissue damage or any other pathophysiological cause.
Pain has several dimensions, including:
- A sensory dimension — Where do you experience pain and how much does it hurt?
- An emotional dimension — How unpleasant is the experience?
- A cognitive dimension — How do you interpret your pain based on previous experiences. Does it cause you fear and/or anxiety? How do you respond?
When it comes to chronic pain, your experience is a complex one, based on sensory, cognitive, and emotional variables. This means that overcoming chronic pain is not just about overcoming structural changes in the body — it’s about overcoming a brain problem. This is why many researchers are interested in healing through neuroplasticity.
This video from Live Active in Australia does a wonderful job of illustrating the complexity of pain:
Chronic Pain Patients May Feel Pain Differently Than Others
Research suggests that in patients with chronic pain, overstimulated pain processing exists making the nervous system more sensitive. In some cases, even a light touch can be perceived as pain. This hypersensitivity causes patients to feel pain more often and more intensely.
Chronic pain is recognized as pain that lasts or recurs for more than 3 to 6 months. Since structural changes in the body, such as tissue, muscle, ligament, or bone damage, will heal as well as they can within 3 to 6 months, chronic pain is more about the sensitivity of the nervous system. If, for example, you break a bone, your nervous system will go into high alert and once the area heals, it resets back to a lower alert setting. However, this is not always the case.
Sometimes, the system will not reset, even after an injury has mended. In this case, your brain has been altered, causing you to feel continuous pain. This helps to explain bizarre situations, like phantom limb syndrome where patients still feel pain in a limb that is no longer there — which is why so many researchers are interested in how the brain rewires itself. If you can interfere with this process, it may be possible to restore it.
One key study also found a link between chronic pain and pain-related symptoms, including anxiety, sleep issues, and poor decision making. It was found that in people with chronic pain, the front region of the cortex, which is associated with emotion, is stuck on full throttle. Neurons wear out and alter their connections. This is just another example of how complex and personal pain is experienced.
While each scenario is unique and chronic pain remains to be a complex topic, one that merits more research, it is important that you continue to understand what chronic pain is so that you can better manage it. In the words of author Cheryl Richardson, “Chronic pain or other challenges are invitations — gifts that challenge us to learn how to manage the mind.”