The Brain and Chronic Pain

Chronic pain is a highly complex experience that can have a broad range of physical and mental effects on the brain and body. With millions across the globe experiencing pervasive and debilitating chronic pain conditions, we explore the psychological and neurological consequences of living with pain. 

Structural and functional brain changes

Being in chronic pain has been associated with reduced levels of grey matter, with sufferers having up to as much as 11% less than those without long-term pain. This reduction in grey matter density compounds over time, meaning that the longer a person has experienced chronic pain, the more grey matter they lose. 

Changes in grey matter density and the proper function of the prefrontal cortex due to prolonged pain can cause issues with a wealth of daily processing tasks, including focus, memory, and learning. In some patients, chronic pain can also affect motor functions, making it difficult to perform everyday activities. 

The HPA Axis

The hypothalamic-pituitary-adrenal (HPA) axis is the body's chief stress response system. Long-term pain can trigger this axis, causing an ongoing state of stress. This activates the release of stress hormones such as cortisol, which flood the body and affect brain function. It can also instigate damage to neurons, and impair the function of the hippocampus, which is fundamental for learning and memory.

Neuroplasticity

The plasticity of the brain is of great use to us in many ways, but chronic pain can rewire the brain in a negative way. With pain that is constant and ongoing, the brain’s perception of pain signals can become dysregulated, potentially causing hypersensitivity and amplified sensations. Over time, the brain may become less adept at interpreting and modulating pain signals, which can lead to difficulties with the self-regulation of chronic pain. 

Cognition and emotion

Understandably, chronic pain also has a significant impact on the cognitive and emotional processing sectors of the brain. Long-term pain conditions often come with a range of difficult mental health issues as a result, including anxiety and depression. A state of continual discomfort can induce a heightened emotional state affecting mood and behavior. 

Managing the vicious cycle

Although chronic pain stems from a physical ailment in many cases, long-term discomfort can exert a powerful impact on the brain’s form and function. Recognizing how the brain’s intricate structures and processes are affected by the experience of protracted pain is key to creating comprehensive pain management strategies, both now and for the future.