Pain assessment is the foundation of pain management. Without understanding what kind of pain a patient is experiencing, what mechanisms are driving it, and what factors are modulating it, treatment becomes guesswork. This text outlines a structured approach to pain assessment that integrates the biological, psychological, and social dimensions of the pain experience.
The first question: believe the report
Pain is what the patient says it is. This is not a philosophical position; it is a clinical one. The patient has access to their pain experience. The clinician does not. Self-report is the gold standard of pain assessment because there is no objective measure that reliably captures pain intensity, character, or impact.
Believing the report does not mean accepting every statement uncritically. It means treating the patient’s experience as the primary data — the observation that any explanation must account for. If a patient reports severe pain and imaging shows no structural abnormality, the clinical question is not “is the patient lying?” but “what mechanism produces pain without visible structural pathology?” Central sensitization, neuropathic processes, referred pain, and functional pain syndromes all answer this question through identifiable neurophysiology.
Structured pain history
A comprehensive pain assessment includes:
Character and location
- Where is the pain? Ask the patient to point. Pain that is well-localized suggests somatic nociceptive origin (musculoskeletal, cutaneous). Pain that is diffuse or poorly localized suggests visceral origin or central sensitization.
- What does it feel like? Descriptors provide mechanistic information:
- Sharp, stabbing, well-localized — likely nociceptive, A-delta fiber mediated
- Dull, aching, deep, diffuse — likely nociceptive, C-fiber mediated, or visceral
- Burning, shooting, electric, tingling — likely neuropathic (nerve damage or dysfunction)
- Widespread, migratory, accompanied by fatigue and sleep disruption — suggests central sensitization syndrome
Temporal pattern
- When did it start? Acute onset suggests injury, vascular event, or infection. Gradual onset suggests degenerative, inflammatory, or sensitization process.
- Is it constant or intermittent? Constant pain suggests ongoing nociceptive drive or sustained central sensitization. Intermittent pain suggests mechanical or activity-related triggers.
- What is the trajectory? Improving pain suggests resolving pathology. Stable pain suggests a maintained process. Worsening pain demands investigation — is the underlying condition progressing, or is the nervous system sensitizing?
Severity and impact
Numeric pain scales (0-10) have limitations — they collapse a multidimensional experience into a single number. More useful questions include:
- What can you do despite the pain? Functional impact matters more than intensity ratings.
- How does the pain affect sleep? Sleep disruption both results from and contributes to chronic pain.
- How does the pain affect your relationships, work, and daily activities? These questions map the social dimension of pain impact.
Aggravating and relieving factors
- What makes it worse? Movement-related aggravation suggests mechanical or inflammatory components. Stress-related aggravation suggests descending facilitation. Touch-related aggravation (allodynia) suggests central sensitization.
- What helps? Rest, heat, ice, medication, distraction, movement, social support — each relieving factor provides mechanistic information.
Prior treatment and response
- What treatments have been tried? What helped, what didn’t, and what made things worse?
- If opioids have been used: for how long, at what doses, with what effect? Is hyperalgesia a possibility?
- Has the patient tried non-pharmacological approaches (physical therapy, somatic practices, acupuncture, psychological intervention)?
Physical examination for pain
The examination should include:
- Observation — posture, guarding, facial expression, movement patterns. Thomas Hanna’s somatic observation framework — identifying green-light (posterior), red-light (anterior), and trauma (lateral) reflex patterns — can reveal habitual muscular tension patterns contributing to pain.
- Palpation — tenderness, trigger points, temperature changes, swelling
- Range of motion — active and passive; discrepancy between them provides information about voluntary guarding vs. structural limitation
- Neurological examination — sensory testing (light touch, pinprick, temperature, vibration), motor strength, reflexes. Findings of allodynia, hyperalgesia, or altered sensation help identify neuropathic and central sensitization components.
- Functional assessment — observe the patient performing relevant activities (walking, sitting, reaching, gripping). Functional capacity may diverge from reported severity in either direction.
Classifying pain by mechanism
Effective treatment depends on identifying the dominant pain mechanism:
| Mechanism | Features | Examples | Treatment direction |
|---|---|---|---|
| Nociceptive | Well-localized, proportionate to tissue pathology, responsive to anti-inflammatories | Acute injury, osteoarthritis, post-operative pain | Treat tissue (anti-inflammatories, surgery, physical therapy) |
| Neuropathic | Burning, shooting, electric; follows nerve distribution; may include numbness | Diabetic neuropathy, radiculopathy, post-herpetic neuralgia | Treat nerve (gabapentinoids, SNRIs, nerve blocks) |
| Nociplastic / centrally sensitized | Widespread, disproportionate to tissue findings, allodynia, hyperalgesia, fatigue, sleep disruption | Fibromyalgia, chronic primary pain, central sensitization syndromes | Treat nervous system (exercise, sleep, somatic retraining, centrally acting medications, psychosocial intervention) |
Most chronic pain involves more than one mechanism. A patient with chronic low back pain may have nociceptive input from degenerative disc disease, neuropathic input from nerve root compression, and nociplastic amplification from central sensitization — all simultaneously. Treatment must address each contributing mechanism.
The assessment as therapeutic act
How pain is assessed affects pain itself. A clinician who listens carefully, takes the report seriously, explains the mechanisms, and communicates a plan activates the patient’s sense of being understood — which, through descending modulation and therapeutic alliance effects, can itself reduce pain. A clinician who rushes through the assessment, expresses skepticism, or attributes pain to psychological causes without explanation produces the opposite effect: threat perception increases, descending modulation shifts toward facilitation, and pain amplifies.
The assessment is the first intervention.