🧠 Understanding Pain: Why Tissue Damage Doesn’t Tell the Whole Story

At The Flow Clinic, we often meet people who feel confused — or worried — because their pain doesn’t seem to make sense. Sometimes scans show “damage” but pain is mild or absent; other times pain feels intense even when imaging looks normal. This isn’t weakness or imagination — it’s how pain science really works.

Let’s explore what modern research tells us about pain thresholds, and why understanding them helps us treat pain more effectively.

Pain Is More Than Just Tissue Damage

Traditionally, pain was thought to equal injury. Twist a joint → damage → pain. But decades of neuroscience show the picture is more complex.

• Nociceptive load — the signals coming from tissues (mechanical stress, inflammation, chemical irritation) that activate nociceptors (Sluka & Clauw, 2016).

• Corticolimbic pain threshold — your brain’s “filter.” Before sensations reach conscious pain, they pass through deep brain areas (limbic system) that decide whether the message seems dangerous or safe (Baliki & Apkarian, 2015).

If the brain judges the input as threatening, the signal breaks through and becomes pain. If the brain feels safe, the same input may stay below the pain threshold.

👉 Two people can have the same tissue strain but very different pain experiences.

What Lowers the Pain Threshold

Pain thresholds aren’t fixed — they shift depending on biological, psychological, and social context (Louw et al., 2016; Moseley & Butler, 2017):

• Stress & emotional load — fear of injury, anxiety, and job or life stress.

• Previous pain episodes — the nervous system can become sensitized (“central sensitization”) (Nijs et al., 2021).

• Poor sleep or illness — reduced recovery, altered immune and inflammatory balance.

• Reduced physical activity — tissues and the nervous system become more reactive.

• Immune system changes — allergy flare-ups, infection, chronic low-grade inflammation.

When these factors accumulate — sometimes called allostatic load — the nervous system becomes “on alert,” lowering the pain threshold. Then normal movement or mild strain can suddenly feel painful.

How Clinicians Gauge Pain Sources

We can’t measure pain directly, but we can triangulate tissue involvement and nervous system sensitivity using:

• Case history & red flag screening — trauma mechanism, constitutional signs (Henschke et al., 2009).

• Orthopaedic and neurological tests — range of motion, resisted testing, reflexes, dermatomes.

• Manual palpation — swelling, heat, guarding, tenderness.

• Graded loading & movement — to find safe movement “windows.”

• Psychosocial profiling — validated screening tools (e.g., STarT Back Tool; Hill et al., 2008).

Sometimes imaging or referral is needed for suspected structural injury — but in many persistent pain cases, sensitivity rather than tissue damage is driving symptoms.

Changing the System: How Treatment Helps

Manual therapy and movement can help raise the pain threshold and reduce sensitivity:

• Gentle, pain-free movement can desensitize tissues and down-regulate the nervous system (Louw et al., 2017).

• Graded loading re-teaches the brain that movement is safe (Moseley & Butler, 2017).

• Education about pain reduces fear and perceived threat (Louw et al., 2016).

• Lifestyle interventions — improving sleep, managing stress, breathing training, regular physical activity — reduce allostatic load (Sluka & Clauw, 2016).

Even spinal manipulation (high-velocity thrust; HVT) can temporarily boost pain thresholds, creating a “window” to move more comfortably (Bialosky et al., 2009).

Real-World Example — “Jared”

In the original teaching case, Jared — a busy professional under heavy work stress, poor winter health, and reduced activity — developed sudden thoracic pain after golf. The tissue strain was modest, but his nervous system was primed: chronic stress, immune challenges, and deconditioning lowered his pain threshold.

Helping Jared involved more than local treatment: education, progressive loading, stress and sleep support, and hands-on therapy to restore safety and resilience.

Key Takeaway

Pain is an output — not a direct “damage meter.” Understanding corticolimbic pain thresholds empowers smarter care: supporting tissues while calming the nervous system and addressing the life factors that amplify pain.

If your pain seems out of proportion or slow to settle, it doesn’t mean damage is ongoing. It might mean your system is on alert — and that’s something we can help change.

References

• Baliki MN, Apkarian AV. Nociception, pain, negative moods, and behavior selection. Neuron. 2015;87(3):474–491.

• Bialosky JE, Bishop MD, Price DD, Robinson ME, George SZ. The mechanisms of manual therapy in the treatment of musculoskeletal pain: a comprehensive model. Manual Therapy. 2009;14(5):531–538.

• Henschke N, Maher CG, Refshauge KM, et al. Prevalence of and screening for serious spinal pathology in patients presenting to primary care with acute low back pain. Arthritis Rheum. 2009;60(10):3072–3080.

• Hill JC, Dunn KM, Main CJ, et al. Predicting outcomes of primary care back pain: development and validation of the STarT Back Tool. Arthritis Care Res. 2008;59(5):632–641.

• Louw A, Zimney K, Puentedura EJ, Diener I. The efficacy of pain neuroscience education on musculoskeletal pain: a systematic review. Phys Ther. 2016;96(9):1249–1268.

• Moseley GL, Butler DS. Explain Pain Supercharged. Noigroup Publications, 2017.

• Nijs J, Malfliet A, Ickmans K, et al. Treatment of central sensitization in patients with chronic pain: time for change? Expert Opin Pharmacother. 2021;22(6):721–734.

• Sluka KA, Clauw DJ. Neurobiology of fibromyalgia and chronic widespread pain. Neuroscience. 2016;338:114–129.