What Happens to Your Brain When You Are in Pain? A Look at the Pain Mechanisms Model
Updated: Nov 2
Pain is an essential part of the human experience, designed to protect us. But have you ever wondered what happens inside your brain when you're in pain? Understanding how pain works can give you real insight into the relationship between pain, your brain and your overall experience, and it's one of the most powerful tools for recovery.
The Power of the Pain Mechanisms Model
The International Association for the Study of Pain (IASP) describes pain as an unpleasant sensory and emotional experience, always influenced by biological, psychological and social factors. Pain and tissue damage are not the same thing.
Pain science now recognises three main pain mechanisms, which can overlap:
Nociceptive pain: From actual or potential tissue damage, such as a sprained ankle.
Neuropathic pain: From injury or disease of the nervous system, such as sciatica or carpal tunnel syndrome.
Nociplastic pain: From changes in how the nervous system processes pain, making it more sensitive, even without clear tissue or nerve damage. This was formally recognised by the IASP in 2017, with clinical criteria published in 2021.
Understanding this helps explain why pain persists, why it can sometimes intensify without new injury and, most importantly, how to break the cycle. Pain is a signal we can decode, not a life sentence we must endure.
The Pain Alarm System
When you touch a hot surface or sprain your ankle, specialised sensors in your body called nociceptors detect potential danger. They send signals through your nerves to the spinal cord and up to the brain. This is often called the 'alarm system'.
However, nociception (danger signals) does not equal pain. Your brain processes these signals and decides whether to produce pain, based on context and how threatening the situation seems.
The Brain's Role in Pain
Once danger signals reach your brain, many regions work together. There's no single 'pain centre':
Sensory areas: Map the location and intensity of the pain.
Emotional and memory networks (the limbic system): Add emotional meaning and link it with past experiences.
The prefrontal cortex: Helps you make sense of the pain and decide how to respond.
This means pain is influenced not just by physical injury, but by emotions, memories, beliefs and context.
Why Pain Is Not 'All in Your Head'
While the brain produces pain, that doesn't mean it's imaginary. Pain is always real and valid, and influenced by:
Biological factors: Tissue damage, inflammation, nerve sensitivity, sleep and general health.
Psychological factors: Stress, worry, low mood and beliefs about pain.
Social factors: Support, work, culture and life circumstances.
The Good News: Your Nervous System Can Change
Neuroplasticity means the nervous system is adaptable. With the right strategies, you can help calm an overprotective alarm system. Evidence-based approaches include:
Pain education: Understanding how pain works reduces fear and improves outcomes, especially when combined with exercise.
Movement and exercise: Gradual, confidence-building movement helps desensitise the nervous system.
Approaches that combine both: Cognitive Functional Therapy (CFT), which we use at MOVE, produced large and lasting improvements for people with persistent back pain in the RESTORE trial (The Lancet, 2023).
Sleep, stress and mindfulness strategies: These reduce the brain's perception of threat.
Professional support: Physiotherapists, psychologists and pain specialists can guide a personalised plan.
A Real-Life Example: Imagine This...
During a long, sweltering car ride back to university after celebrating a basketball grand final win, I experienced back pain like I'd never felt before. What started as a dull ache turned into shooting pain down my leg, with muscle spasms. I hadn't injured myself, yet the pain lingered for weeks, unpredictable and frustrating. Doctors called it non-specific low back pain, meaning there was no single clear cause.
The environment mattered
Imagine driving alone for hours in 40-degree heat with broken air conditioning, sticky car seats and no sleep after a night out. Add stress about an upcoming exam, and replaying a conversation with a relative whose back pain had ended their sporting career. All of this created a perfect storm. My brain was processing these stressors as threats and turning up the volume on signals from my back.
Body signals
Sitting in one position for hours makes muscles and joints stiff, and nociceptors send signals about potential danger. Add dehydration, heat and a hangover, and the body becomes more sensitive. It's like turning up the volume on your internal alarm.
How It Felt
How I felt
The pain wasn't just physical. I felt fear (what if this never goes away?), frustration (why can't I move like I used to?) and uncertainty about my future as an athlete and physio. Those 'what ifs' amplified the experience.
How I reacted
Out of fear of making things worse, I moved cautiously, constantly adjusted my posture and avoided bending. These behaviours felt protective, but they reinforced my brain's belief that something was seriously wrong.
How my body responded
My heart raced, my muscles tensed and I even felt nauseous. These were my body's way of trying to protect me.
Why the Pain Stuck Around
Pain can become a cycle. Fear, stress and poor sleep kept feeding the loop, making my body more sensitive to normal movements like sitting or bending. Imagine an overly cautious alarm that keeps going off, even when there's no real danger. This is why pain can sometimes feel worse over time without further injury.
Why Understanding Pain Helps
Understanding your pain: Instead of fearing it, you see it as your body's way of protecting you, and learn that movement isn't harmful and can actually help.
Retraining your system: By gradually moving and challenging unhelpful beliefs, you turn down the volume on an overactive alarm.
Feeling in control again: Knowing pain can change gives you the confidence to take proactive steps.
For me, understanding what was happening allowed me to start gentle, graded exercise, rebuild confidence in my back, and use strategies to reduce stress. Over time, my nervous system settled and my pain eased.
Understanding Your Pain
If you're living with persistent pain, remember: pain is real, but it's also something you can influence.
Start exploring gentle movements that feel safe and manageable.
Work with a physiotherapist who understands modern pain science and can tailor a plan for you.
Explore trusted resources that explain pain science in easy-to-understand ways. Knowledge is empowering!
Pain Is Real, and It Can Change
Pain is a complex, brain-and-body experience that involves much more than physical injury.
By understanding how pain works, you can take proactive steps to manage it and get back to living well.
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