A 7-part Series on Chronic Pain

by Josh Meyers, PT, DPT, OCS

Pain is good. It helps one to avoid danger, survive an injury, and protect oneself when confronted by physical or emotional threats. The problem arises, however, when pain persists after a danger is removed, an injury heals, or a threat is no longer present. Medical providers call this persistent type of pain chronic pain, and it is the leading cause of disability in America.

Hope, however, lies in the fact that chronic pain is treatable. Through this series, readers will learn how chronic pain develops, recognize common symptoms, and understand how chronic pain is treated. Our goal is to empower readers to take action and regain control of their pain. Comments at the end of each post are welcome. Be sure to ask questions and share experience to help others with similar symptoms.

Part 1: The Body’s Alarm System

Imagine a house alarm system. Cameras and sensors constantly monitor the inside and outside of the house for any signs of movement, vibration, or break-ins. The video recorder in the backroom records and processes every piece of input for everything that happens around the house. As long as no sound or vibration trips the system, the alarm system continues to function, unnoticed. When an input does trip the system, however, the alarm sounds to alert the homeowner that danger is present.1,2,3

Each person’s nervous system monitors the body and the surrounding environment in the same way. Nerves constantly send signals (input) to the brain about movement, pressure, temperature, and the environment. Most of the time, these signals come in at a level where the brain is not consciously aware of them. (Notice how the awareness of a band-aid on the skin fades after time.) When a signal comes in that the brain does perceive to be a threat, however, the brain sounds the alarm by causing a pain experience.1,2,3

Here is how this plays out in real life. Imagine someone is walking along and steps on a nail. What happens? As soon as the foot hits the nail, the body’s alarm system activates and says, “Danger, danger, you are stepping on a nail.” This alarm system may produce pain or cause the person to be extra focused on the location of the foot. Either way, the alarm signals danger and compels the person to remove the foot from the nail. At this point, the alarm system has done its job. As the swelling and inflammation in the bottom of the foot subside over the next several hours or days, the alarm system settles back down to its normal, quiet level of monitoring.1,2,3

Sensitive Alarms

In people with chronic pain, however, the alarm system does not settle back down. Researchers have a guess as to why this happens (genetic factors or past experience), but what they are sure of is that 1 in 4 people have an alarm system that tends to stays active or extra sensitive after an injury or traumatic experience. Pain continues to be present (the house alarm does not shut off) or shows up with little reason (a leaf blowing by sets off the extra-sensitive alarm) even after a threat or danger is gone. This increased type of sensitivity is called hypersensitivity.

While a house alarm follows a simple algorithm, the brain is a little more complicated. A hard-wired house alarm sounds an alarm when an input reaches a certain threshold – simple and predictable. The brain, however, constantly adjusts or changes its alarm threshold in response to emotions, experiences, expectations, or situations. Scientists call this ability to change neuroplasticity. Neuroplasticity is helpful because it allows us to learn from our experiences and react more quickly during similar situations in the future. (Imagine never remembering that stoves are hot.) Problems arise, however, when neuroplasticity allows the brain to become hypersensitive and cause a pain experience prematurely or unnecessarily.

Furthermore, in people with a properly functioning alarm system, there is much room for activity (movement, stress, fatigue) before the alarm sounds. People can push limits of physical exertion, stress exposure, or sleep deprivation without an alarm going off. For people with hypersensitivity though, there is a small window for activity (movement, stress, fatigue) before the alarm trips. Practically speaking, this means that people with hypersensitivity experience pain more quickly than others, or it takes less activity for a person with hypersensitivity to experience pain.1,2,3

Managing vs. Treating

When it comes to hypersensitive alarm systems, the goal is to treat them, not manage them. Managing a sounding house alarm would be the equivalent of giving a person ear plugs (opioids), turning up the radio (TENS units), or trying to ignore the sounding alarm (“It’s all in your head, there’s nothing wrong with you.”) Opioids and TENS units have some short-term value to allow one time to determine why an alarm is sounding, but none of the above strategies are effective tools for long-term pain management. Treating a sounding house alarm must actually strive to turn off the alarm by decreasing the volume and restoring normal sensitivity levels. Subsequent posts will address how one goes about doing this. 

In summary, alarms are only useful when they alert a person of a present danger. An alarm that continues to sound after a danger is no longer present is not only useless, it is annoying. Chronic pain is one such alarm. When pain remains after a threat or injury has been removed, it serves no purpose of protection and impairs one’s ability to function.

In the next post, readers will learn how the wiring of this alarm system directly affects pain. 

Need Help?

If you suffer from chronic pain, there is hope. Call us today to find out how physical therapy can help treat your chronic pain.

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References:

  1. Louw A, Zimney K, O’Hotto C, Hilton S. The clinical application of teaching people about pain. Physiotherapy Theory and Practice. Jul 2016;32(5):385-395.
  2. Louw A, Puentedura E, Zimney K, Cox T, Rico D. The Clinical Implementation of Pain Neuroscience Education: A Survey Study. Physiotherapy Theory and Practice. 2017 – accepted for publication.
  3. Louw A. Why You Hurt Therapeutic Neuroscience Education System. Minneapolis, MN: OPTP; 2014.