Scientists discover why chronic back pain feels so personal

Researchers at UC San Diego School of Medicine found that movement-triggered pain in people with chronic low back pain (cLBP) activates a brain network that normally becomes less active during ordinary pain. The discovery suggests that persistent back pain may become deeply intertwined with a person’s sense of self, potentially helping explain why conventional pain treatments often provide limited relief.

According to the World Health Organization, low back pain is the leading cause of disability worldwide. When pain persists for more than 12 weeks, it is considered chronic. For many patients, everyday movements can provoke sudden flare-ups that make an already difficult condition even harder to manage.

Although the brain plays a central role in how pain is experienced, researchers have struggled to identify the precise brain circuits responsible for pain triggered by movement.

Chronic Back Pain Activates the Brain’s Sense of Self

The new study, published on October 5, 2026, in the British Journal of Anaesthesia, identified an unexpected response involving the brain’s Default Mode Network (DMN).

Sometimes called the “self network,” the DMN consists of interconnected regions in the frontal, parietal, and temporal lobes. These areas are especially active when our attention turns inward, such as when we reflect on personal experiences, think about our identity, or consider our thoughts and emotions. In contrast, the network generally becomes less active when we direct our attention toward something happening around us.

The researchers discovered that sudden back pain caused by movement switched this network on rather than off. This unusual response suggests that chronic pain involves more than the processing of physical sensations. It may also engage the brain systems that shape how people experience themselves.

The findings could help researchers understand why treatments that focus primarily on suppressing pain symptoms do not always work well for chronic low back pain. They also raise the possibility that targeting the DMN could offer a different approach to treatment.

Brain Scans Reveal a Surprising Difference Between Chronic and Acute Pain

To investigate what happens in the brain during a pain flare, the researchers recruited 114 patients with chronic low back pain.

Each participant completed a “leg raise test,” a standard clinical procedure used to provoke back pain. During the test, researchers monitored changes in brain blood flow using a specialized functional MRI method called arterial spin labeling. This technique allows scientists to track patterns of brain activity by measuring blood flow without relying on an injected contrast agent.

The team also examined how participants responded to a separate painful stimulus. They applied a harmless but uncomfortable heat sensation to the calf, similar to the brief pain someone might experience when accidentally touching a hot stove.

Comparing these two situations revealed a striking difference.

When movement triggered a flare of chronic back pain, the DMN became more active. However, when participants experienced the painful heat stimulus, the same network became less active, following the brain’s typical response to acute pain.

The researchers also identified several other important patterns:

• Patients with more severe chronic back pain showed stronger connections between the DMN and the primary somatosensory cortex, a brain region responsible for processing physical sensations, including signals from the back.
• Greater pain intensity during the leg raise test was associated with increased activity in brain regions involved in sensation and movement.
• Increases in heart rate during the test reliably reflected the intensity of the pain flare.

Together, these findings provide new evidence that chronic pain flares involve brain processes associated with personal identity, not just the physical experience of pain.

Why the Brain Reacts Differently to Chronic Pain

During ordinary acute pain, the brain generally reduces activity in the DMN so it can concentrate on the immediate source of danger. This response helps shift attention away from internal thoughts and toward an external threat.

But the UC San Diego researchers found that movement triggered chronic back pain produced the opposite effect.

“In every pain study, when you’re experiencing pain, the DMN deactivates,” said corresponding author Fadel Zeidan, PhD, professor in the Department of Anesthesiology, endowed professor at the Sanford Institute for Empathy and Compassion, and director of the Pain Health and Mindfulness Laboratory at UC San Diego School of Medicine. “What we show for the first time ever is that when you have a pain flare, it turns on instead. You start to identify the experience with who you are.”

The findings suggest that chronic back pain can become closely connected with the brain’s internal representation of the self. Rather than processing pain solely as a physical warning signal, the brain may also link it to personal memories, expectations, and emotional experiences.

For someone living with chronic pain, this means the experience can extend far beyond the moments when the pain is physically present. Worry about the next flare, memories of previous episodes, and fear of movements that might trigger pain can all become part of everyday life.

“The moment-to-moment experience is contaminated not only by the feeling of pain, but by the anticipation of it and recovery from it. It’s contaminated by past experiences like embarrassment about not being able to participate in normal activities and fear of movement when trying to avoid the pain.”

This connection between pain and personal identity may help explain why chronic back pain can be especially difficult to treat.

A New Direction for Chronic Back Pain Treatment

Because movement-triggered chronic back pain engages different brain networks from ordinary acute pain, researchers believe traditional treatments may fail to address some of the processes that sustain the experience of chronic pain.

Medications such as opiates primarily target pain signaling, but they may not adequately address the brain networks involved in the emotional and personal dimensions of persistent pain.

“Current pain medicine is fixated on ridding patients of their pain symptoms, but that’s not the source of chronic pain. These data suggest that a chronic pain flare also encompasses one’s identity.”

The discovery points toward treatments that address not only the sensation of pain but also the brain’s relationship with that sensation.

Recent work by Zeidan and his colleagues has explored two potential approaches: mindfulness meditation and the psychedelic compound psilocybin.

Both approaches are being investigated for their ability to help people experience physical pain without allowing it to become as closely tied to their identity. Early findings suggest that changing this relationship may reduce pain intensity, although additional research is needed to confirm the results and determine how effective these treatments may be.

“These types of mind-body and psychedelic medicine approaches target the whole person,” Zeidan said. “Mindfulness is a meditation technique that’s about cultivating non-judgmental awareness of the present moment that dramatically reduces pain in a very unique way. Psilocybin seemingly resets the pain system that integrates trauma, past experiences and future worries to facilitate a restart, if you will. They’re not a silver bullet — you’re not necessarily getting rid of the pain, but you’re changing the relationship you have with that pain so it doesn’t contaminate your everyday life.”

Can Mindfulness and Psychedelics Change How the Brain Experiences Pain?

Rather than attempting to eliminate every pain signal, these approaches aim to change how the brain interprets and responds to the experience.

Mindfulness meditation encourages people to observe their thoughts, emotions, and physical sensations without immediately judging or reacting to them. Psilocybin, meanwhile, is being studied for its potential to alter brain processes that connect pain with earlier experiences, emotional distress, and expectations about the future.

The goal is not necessarily to remove pain altogether, but to reduce how much it influences a person’s thoughts, emotions, and daily functioning.

Zeidan’s laboratory is currently conducting several clinical trials using brain imaging to investigate whether mindfulness meditation and psychedelic treatments can change the neural processes involved in self-reflection. Researchers hope to determine whether these approaches can reshape brain activity and improve how people subjectively experience chronic pain.

Although the research remains at an early stage, the findings offer a different way to think about persistent back pain. Understanding why the brain connects chronic pain with a person’s sense of self could eventually help scientists develop treatments that address aspects of pain that conventional therapies often miss.

Additional study authors from UC San Diego School of Medicine include Morgan Gianola, Jon Dean, Conan Chen, Daniel Barrows, Gabriel Reigner, and Thomas Liu.

Funding was provided in part by the National Institutes of Health’s National Center for Complementary and Integrative Health (Grant #R01AT009693) and the UC San Diego Sanford Institute for Empathy and Compassion. The researchers reported no conflicts of interest.