Pain is one of the most common reasons people seek medical care, yet it is also one of the most misunderstood experiences in healthcare. Many patients believe that pain always means injury, damage, or something “serious” is wrong. Modern pain science has clearly shown that this belief is incomplete and often misleading.
Today, evidence-based physiotherapy uses a modern understanding of pain that helps patients recover faster, move with confidence, and reduce fear. This article explains pain in a clear, science-based, and patient-friendly way—without myths, exaggeration, or false promises.
What Is Pain? – The Modern Scientific Definition.
According to the International Association for the Study of Pain (IASP, 2020), pain is defined as:
“An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”
This definition is important for two reasons: -
Pain is always a real experience.
Pain does not require actual tissue damage to exist.
In other words, pain is not simply a signal coming from injured tissues. It is a complex experience created by the nervous system, especially the brain.
The Old Model vs the Modern Model of Pain: -
The Old (Outdated) Model
For many years, pain was explained using a simple model: -
Pain equals tissue damage.
More pain means more injury.
Rest until pain disappears.
This model fails to explain:
Chronic pain that lasts months or years.
Severe or chronic pain with normal scans.
Why some people recover quickly, while others don’t.
The Modern (Evidence-Based) Model
Modern pain science shows that: -
Pain is produced by the brain.
Pain is influenced by biological, psychological, and social factors.
Pain is a protective response, not a damage meter.
This approach is known as the Biopsychosocial Model of Pain, first proposed by George Engel (1977) and widely adopted in pain research and rehabilitation since the early 2000s.
How Pain Is Actually Produced: Step-by-Step
Pain does not travel directly from injured tissues to the brain. Instead, it is processed through multiple stages.
1. Tissue Signals (Nociception)
Specialized nerve endings called nociceptors detect: -
Mechanical pressure.
Temperature changes.
Chemical irritation.
These signals are not pain. They are simply information sent to the nervous system.
2. Spinal Cord Processing
Signals travel to the spinal cord, where they can be:
Increased.
Reduced.
Completely blocked.
This process is influenced by factors such as: -
Stress levels.
Fear and anxiety.
Previous pain experiences.
Sleep quality.
This mechanism was explained in the famous Gate Control Theory of Pain by Melzack and Wall (1965).
3. Brain Interpretation
The brain receives all incoming information and asks a critical question: -
“Is the body in danger?”
If the brain believes protection is needed, it produces pain.
If not, pain may not be produced—even if tissues are sending signals.
Pain is the brain’s protective decision, not a direct measure of damage.
Pain Does Not Always Mean Tissue Damage
One of the strongest findings in modern research is that pain and tissue damage often do not match.
Key Research Evidence
Jensen et al., 1994 (New England Journal of Medicine)
Found disc herniations in people with no back pain.
Brinjikji et al., 2015 (Spine Journal)
Showed that disc bulges, degeneration, and arthritis are common in pain-free adults.
Heneweer et al., 2011
Reported poor correlation between pain intensity and tissue findings.
These findings mean that many changes seen on MRI or X-ray are normal age-related variations, not necessarily the cause of pain.
Acute Pain vs Persistent (Chronic) Pain
Acute Pain
Short-term.
Related to injury, inflammation, or surgery.
Protective and useful.
Usually settles as tissues heal.
Persistent (Chronic) Pain
Lasts longer than expected healing time (usually beyond 3 months).
Involves changes in the nervous system.
Pain can continue even after tissues have healed.
This phenomenon is called central sensitization, explained by Woolf (2011).
Central Sensitization Explained Simply
Imagine a home alarm system: -
In acute pain, the alarm rings when there is a real threat.
In persistent pain, the alarm becomes too sensitive and rings even when the threat is minimal.
The nervous system becomes:
More sensitive.
Faster to trigger pain.
More protective than necessary.
This does not mean pain is imaginary. It means the nervous system has learned to overprotect.
Why Stress, Fear, and Beliefs Influence Pain?
Pain is influenced by the entire nervous system, not just tissues.
Research shows:
Fear of movement increases pain and disability (Vlaeyen & Linton, 2000).
Chronic stress increases pain sensitivity (McEwen, 2007).
Poor sleep worsens pain perception (Finan et al., 2013).
This is why pain education is considered a core treatment, not just advice.
How Modern Physiotherapy Approaches Pain.
Top evidence-based physiotherapists do not treat pain by focusing only on the painful area. They assess the whole person.
Key Components of Modern Physiotherapy
1. Pain Education
Understanding pain reduces fear and improves outcomes.
Louw et al. (2011) showed that pain neuroscience education can reduce pain and disability.
2. Graded Movement Exposure
Avoiding movement weakens the body and increases fear. Gradual, guided movement restores confidence and function.
3. Strength and Load Tolerance
Tissues adapt to load when applied gradually. This principle is supported by Wolff’s Law and modern rehabilitation research.
4. Nervous System Regulation
Breathing, pacing, and movement variability help calm an overprotective nervous system.
5. Individualised Care
There is no one-size-fits-all treatment. Each patient’s pain experience is unique.
Why Passive Treatments Alone Are Not Enough
Passive treatments such as heat, machines, or massage may provide short-term comfort. However, long-term recovery requires active participation.
A systematic review by Hayden et al. (2005) showed that exercise-based approaches are more effective for long-term outcomes in back pain.
Modern physiotherapy uses passive treatments as supportive tools, not stand-alone solutions.
Key Takeaways for Patients
Pain is real, but not always damage.
Scans do not define recovery.
Movement is safe when guided.
Understanding pain reduces fear.
Recovery is a process, not a quick fix.
Note: -
“This information is for educational purposes only and does not replace a personalised assessment by a qualified healthcare professional.”