The Stress-Pain Cycle
What is the stress-pain cycle? Pain is one of the biggest driving forces that causes patients to seek physical therapy intervention. Whether it is from a traumatic injury, overuse, degeneration, post-surgery, or other factors, the vast majority of cases our physical therapists treat is musculoskeletal pain.
But what about the effect of STRESS on pain? No doubt, we are living through stressful times. Perhaps now more than ever, understanding the connection between stress, our response to it, and the symptoms of chronic pain is critical. In this special three part Stress & Pain series, we aim to explore the antagonistic relationship between pain and stress, its unwanted effects, and how to break the cycle.
Understanding Stress
First, let’s make a distinction between pain-related stress, and non-pain related stress: Pain-related stress refers to a person’s fear and perception of their physical pain. Studies show that if a person exaggerates their response to pain-related stress, it can heighten their physical pain and impede/lengthen recovery. Non-pain stressors include work, family, financial, and other personal sources of stress. If amplified, these too can increase the pain and inhibit healing.
The Role of Cortisol
It is important to understand the basics of what happens when there is a stress response. When we are presented with a stressful situation, our brain signals a release of specific hormones that help us manage, cope with, and/or avoid the hazardous stimulant. Cortisol, produced in the kidney, is one of these hormones. It helps us maintain blood glucose levels that regulate our energy and support proper organ function. Cortisol is also strong anti-inflammatory agent. When we are presented with a physical or psychological stressor, our cortisol levels increase. Therefore, cortisol is effective for helping us to manage short-term strain.
However, cortisol can be dangerous when released over a prolonged period of time due to chronic stress. Lengthy exposures to stress or repeated instances of stress can lead to cortisol dysregulation. This can happen if the stressor is physiological or psychological.
One animal study found that a decreased corticosterone (cortisol equivalent in rats) response occurred after eight days to two weeks of exposure to a stressful stimulus. When the cortisol response malfunctions in humans, there can be an unregulated inflammatory response, which can lead to various dangerous outcomes including free radical damage, cell death, and tissue degeneration. Stress-induced inflammation is connected to various disorders, including chronic low back pain, TMJ pain, chronic pelvic pain, fibromyalgia, osteoporosis, and rheumatoid arthritis, among others. Specific symptoms of stress-induced inflammation include tissue degeneration, low blood pressure, fatigue, depression, and pain. Therefore, we see this cycle:
The Stress-Pain Cycle
Prolonged stress –> cortisol dysregulation –> adverse symptoms and potential disorders –> pain (which itself is also a stressor).
…Coming Up
The next blog post in the Stress & Pain series will discuss what pain is, and explore acute and chronic responses to pain. This will allow us to better understand and treat the effects of stress on pain.
Sources:
1.) Hannibal KE. Bishop MD. Chronic stress, cortisol dysfunction, and pain: a psychoneuroendocrine rationale for stress management in pain rehabilitation. Physical Therapy. 2014; 94:1816-1825.
2.) Crofford LJ. Chronic pain: where the body meets the brain. Transactions of the American Clinical and Climatological Association. 2015. 126:167-179.