The pain response exists to protect our bodies from harm. Pain manifests in the brain and is based on multiple variables. Some variables are involved with past experiences and can change intensity, duration, and perception of pain, while other variables are based on how areas away from our brain are receiving information from our environment. Generally speaking, pain is a sign that we should discontinue activity or change our body position to avoid further damage. Most pain signals are temporary and can be remedied with the appropriate intervention.
Tissue injury or Nociception
Tissue injury is a local disruption of body tissue that leads to an inflammatory response. This inflammatory response activates local nerves which send signals to our spinal cord and eventually our brain where we experience pain. Most often it is from damage to skin, muscle, tendon, ligament, bone, joint capsule, or nerve if it involves the musculoskeletal or integumentary system. Our organs can also be sources of localized tissue injury or can refer pain to other regions of our body. One way to help determine the source of local tissue injury is to move the affected area and see if it changes what type of pain or the level of pain you are experiencing. Pain at rest is indicative of a prolonged inflammatory response, sub-optimal posture, or can indicate something more serious and should be addressed immediately.
Chronic pain is a maladaptive response based on the perception of pain for a prolonged period of time: usually defined as 3 months or longer. Chronic pain often begins by local tissue injury and an inflammatory response.
As a result, it is common to avoid irritating the injured area and even try to protect it. This behavior reinforces the idea that there is injury, even if the area is physiologically healed. As this type of behavior continues, the area can become hypersensitive to stimuli. As an example, if I bump my elbow and it hurts for a few days, I may carry that arm closer to my body, or use my other arm to protect it to avoid hurting it more. If I do bump it one day by mistake, I will have an intense pain response based on the BELIEF that it is still injured even if that’s not true. If this continues long enough, eventually nerves near the area, and our spinal cord will respond more intensely if the area we believed to be injured is stimulated.
Over time, even our brains begin processing pain at a lower level of stimulation, and eventually the area in our brain responsible for that specific body part enlarges. This phenomenon causes us to experience pain in an area without even stimulating it. The biggest issue for people experiencing chronic pain in my experience is that providers don't believe them because local tissue damage is not present. THE PAIN IS REAL. The pain is as real as if there were local tissue damage. It takes conscious disagreement with what you are perceiving to change this type of pain response.