How does trauma affect chronic pain?

Can trauma cause chronic pain?

Trauma raises the risk of chronic pain. Whether it causes it, in the direct way a fracture causes pain, is a harder question, and the research does not yet answer it. What the research does show, repeatedly, is an association large enough that no one studying chronic pain can ignore it.

A 2014 meta-analysis pooled dozens of studies and found that people who reported trauma exposure were roughly 2.7 times more likely to have a functional somatic syndrome, a group that includes fibromyalgia, irritable bowel syndrome, chronic fatigue and chronic widespread pain. The association was strongest for people who met criteria for PTSD. A separate systematic review found that PTSD is consistently more common in people with chronic pain than in people without it, though the rate varies a great deal depending on the kind of pain and how it began. And the original Adverse Childhood Experiences study, which surveyed more than 9,000 adults in a California health plan, found a graded relationship between the number of categories of childhood adversity a person reported and their risk of a long list of adult health problems.

Three cautions. Most of these studies ask people about trauma and pain at the same time, so they cannot show which came first. Most rely on self-report, which is the only practical way to ask about trauma but introduces its own biases. And an association at the population level says nothing certain about any one person: plenty of people with trauma histories never develop chronic pain, and plenty of people with chronic pain have no trauma history at all.

How does trauma change the nervous system?

The short version: a nervous system learns from experience how dangerous the world is, and trauma is a very loud lesson.

The brain's threat system is not fixed at birth. It is calibrated by what happens to the person, and it is calibrated most strongly by events that were overwhelming, inescapable or repeated. After enough of those, the system settles into a different baseline: faster to alarm, slower to stand down, and more inclined to read ambiguous signals as threats. Clinicians call the result hypervigilance, and pain researchers call its sensory counterpart sensitization, a state in which the pain system responds to ordinary input as if it were dangerous.

In the predictive-processing account that this series is built on, there is a more specific way to say this. The brain works by predicting what its senses will report and correcting the prediction when the senses disagree. Each prediction carries a weight, which researchers call precision: how much the brain trusts the prediction against the incoming evidence. Trauma appears to install high-precision predictions about danger. The body is unsafe. This movement will hurt. That sound means something bad is about to happen. Once a prediction is weighted heavily enough, the brain tends to perceive what it predicts, and contradicting evidence from the body gets discounted. Our guide to predictive coding walks through the framework; it is a framework, with growing but incomplete evidence, and it should be read as a useful model rather than a settled mechanism.

Asmundson and Katz, reviewing why anxiety disorders and chronic pain so often occur together, describe a shared-vulnerability model with a mutual-maintenance loop: a tendency to fear bodily sensations, hypervigilance to threat, and avoidance of anything that might trigger it, each of which keeps both conditions going. A person who has learned that their body cannot be trusted monitors it closely. Close monitoring finds more sensations. More sensations, read through a threat prior, become more pain. More pain confirms that the body cannot be trusted.

None of this is a character flaw or a choice. It is what a learning system does when it has been taught, convincingly, that danger is close. The same learning capacity that installed the lesson is what makes it possible to revise. Our page on nervous system dysregulation covers the wider picture, including sleep, digestion and fatigue.

Why does an injury at work or in an accident sometimes become chronic?

Because the injury and the fear were learned together, and the brain stores them together.

Consider a warehouse worker whose hand is caught in a conveyor. The tissue damage is real and it heals over a few months. Two years later, the hand still hurts, and it hurts most when he reaches for something at shoulder height, in a room that smells of machine oil, when a motor starts up behind him. An MRI shows nothing that explains it. He has been told, more than once, that there is nothing wrong.

Memory researchers distinguish between two ways the past shows up. Recollection is the replay: the full episode returns, with its images and its dread, and the person knows they are remembering. Familiarity is quieter. There is no scene, just a feeling that this situation is bad, arriving before any conscious thought. Pain that returns in the place where an injury happened, or during the movement that was underway when it happened, often rides on familiarity. Nothing is remembered. The body simply braces, and the brain reads the bracing as confirmation.

This is why context matters so much in chronic pain, and why the same movement can be fine in one setting and unbearable in another. The worker may be able to reach for a glass in his own kitchen but not for a box at work, with the same shoulder and the same hand. The difference is not in the tissue. It is in which predictions the context switches on. It is also one reason pain that began in a frightening setting, an accident, an assault, a workplace injury, can run a longer course than the same injury sustained while playing with a grandchild.

Much of this learning happens below awareness, which is also why reassurance alone rarely fixes it. The worker does not believe, in words, that reaching will re-injure him. His nervous system believes it anyway. Karuna takes workers' compensation referrals, and the care team confirms coverage case by case; our guide to kinesiophobia covers the fear-of-movement side of this in detail.

How does trauma change the sense of self?

A running theme of this series is that our sense of self is constructed, moment to moment, from the same predictive machinery that produces perception, and that chronic pain builds a different self. Trauma does the same thing, and the two can build on each other.

Think about what a self is made of. A continuous feeling of being this body, in this place, with this history, and a running story about who that person is. All of it is assembled from predictions: about what the body will feel like, about what will happen next, about what kind of person one is. For someone who was hurt badly, especially repeatedly or in childhood, the predictions at the base of that structure were learned in a world that was not safe. The self that gets built is a self organized around not being safe. It scans. It braces. It expects the next thing to be bad, because the next thing usually was.

Add chronic pain, and the two reinforce each other. The pain self says the body is broken and movement is dangerous. The trauma self says the body is where bad things happen and the world cannot be trusted. Together they produce a person who has every reason to stay still, stay guarded and stay out of their own body.

That last part deserves attention. Many trauma survivors describe a habit of stepping away from their body: going numb, feeling far away, watching life from behind glass. Clinicians call this dissociation, and it is one of the mind's oldest ways of surviving the unsurvivable. It was adaptive. The difficulty is that a nervous system cannot update its predictions about a body it refuses to attend to. Interoception, the brain's reading of signals from inside the body, becomes either muted or alarmed, with little in between. Minor signals get missed until they are loud, and loud signals get read as catastrophe.

This is why body-awareness work has to be handled with care in a trauma history. Attention to the body can feel like walking back into the room where it happened, so the goal is to help someone find it safe to be in their body at all, a little at a time. Our guide to the sense of self in chronic pain takes the wider story further.

What does trauma-informed pain care look like?

Trauma-informed care is a way of delivering any treatment, rather than a treatment in itself. SAMHSA's 2014 framework describes it as care that realizes how common trauma is, recognizes its signs, responds with practices that account for it, and actively resists re-traumatizing the people it serves. Its core principles are safety, trustworthiness and transparency, peer support, collaboration, voice and choice, and attention to cultural, historical and gender context.

Applied to chronic pain, that produces a fairly specific picture of what a program should and should not do.

A few things follow. No forced exposure, ever: graded exposure to movement works because the person chooses each step, and an exposure that is imposed teaches the nervous system that the clinic is one more place where things are done to you. Body-awareness exercises are offered, not required, and are introduced with an exit. A flare is treated as information, not as a lapse. And the program should know its limits. A pain program is not where trauma gets processed. That is the work of a trauma therapist, and good pain care coordinates with that therapist rather than trying to replace them.

Medication stays with the prescriber. A pain program, trauma-informed or otherwise, should never advise starting, stopping or changing a medication, including those prescribed for PTSD, anxiety, depression or sleep. Those decisions belong in a conversation between the person and whoever prescribes for them.

How does therapeutic neuroscience treat pain with a trauma history?

The therapeutic neuroscience approach starts from the idea that chronic pain is maintained by predictions about danger, and that predictions change when the brain gets repeated, convincing evidence that contradicts them. With a trauma history, the evidence has to be delivered with more care, because the predictions were learned in conditions where the person had no control, and treatment that repeats that pattern tends to confirm them rather than revise them.

So the work is built from graded, chosen, embodied experiences of safety. Graded, because the step size matters and small steps that succeed teach more than large steps that overwhelm. Chosen, because control is the one thing the original experience took away, and restoring it is part of what makes the new experience different enough to count. Embodied, because the predictions being revised are about the body, and words alone update them slowly if at all. Education helps people make sense of what is happening to them, which lowers the threat of the sensations themselves; our commentary on pain neuroscience education covers what that can and cannot do on its own.

Where VR embodiment fits

Virtual embodiment has one property that matters here. It is a controllable environment. In a headset, a person sees and moves a virtual body in a space that contains nothing from the room where the injury happened, with movements that can be scaled down to a range that feels safe and expanded only as fast as the person wants. The headset comes off the moment anyone wants it to. Karuna's VR exercises are designed to create safe prediction errors around movement, moments where the brain expects pain or harm and gets neither, and to retrain the brain's map of the body over repeated sessions. Why that might work is covered in our commentary on virtual embodiment and pain.

Karuna Virtual Embodiment Training (KVET)™ runs for 12 weeks at home, with short daily VR sessions on a provided headset, a weekly one-on-one session with a pain coach, and a clinician who reviews each case before the program begins and oversees it throughout. The pace of exposure is set with the coach, not imposed, and the clinician review is where a trauma history and any current mental health care get discussed. Program details and Karuna's outcome data, with its limits spelled out, are on how it works.

What this means for you

If you have a trauma history and chronic pain, the research says your nervous system has good reasons for being on guard, and that the guarding is part of what hurts. That is a reason for care that takes both seriously, not a reason to doubt yourself.

• Get the tissue checked, and keep getting it checked when something changes. A trauma history does not protect you from the ordinary causes of pain. See a doctor promptly for new weakness or numbness, loss of bowel or bladder control, unexplained weight loss, fever, pain after a major injury, or chest pain.
• You do not have to tell your pain story to get pain care. A trauma-informed clinician needs to know that there is a history so they can pace the work; they do not need the details unless you choose to share them.
• You can say stop. In any program, in any exercise, with anyone. A clinician who does not accept that is the wrong clinician.
• Trauma therapy and pain care go together. If you are already working with a therapist, tell your pain team, with your permission, so the two can coordinate. If you are not, and PTSD symptoms are active, that care comes first. Expect progress to be uneven: anniversaries, stressful periods and reminders can bring the pain back, which is the nervous system doing what it learned to do, not evidence that the work has failed.

For clinicians: ask about trauma in the way SAMHSA suggests, which is to assume it may be present rather than to interrogate. Offer body-focused work with an exit. Treat avoidance as learned protection to be worked with, not resistance to be overcome. And hold the line on scope: pain care that drifts into trauma processing without training can do harm.

If you want to think out loud about what living alongside pain and a hard history has been like, Karuna's ACT coach is a short, private conversation built on acceptance and commitment therapy principles. It is a place to start, not a treatment and not a crisis service.