Pain Assessment, Diagnosis, and Multidimensional Evaluation
Structure the evaluation around mechanism and function
Pain assessment is not a pain score; it is a hypothesis-generating process. Take a focused history of onset, location, quality, timing, aggravating and relieving factors, severity, prior treatments, and - critically - functional impact (sleep, work, mobility, mood). Classify pain by mechanism: nociceptive (somatic or visceral), neuropathic (burning, shooting, electric, with sensory changes), and nociplastic (widespread, disproportionate, central sensitization). Use validated instruments appropriately: a numeric rating scale for intensity, but PEG (Pain, Enjoyment, General activity) or pain interference measures for function. Screen for psychosocial yellow flags - catastrophizing, fear-avoidance, depression, anxiety, PTSD, substance use - because they predict chronification and response. Examine for neurologic deficit, gait, tenderness, and referred patterns.
Red flags change the pathway: saddle anesthesia, bowel or bladder dysfunction, progressive weakness, fever, unexplained weight loss, cancer history, trauma, or night pain unrelieved by rest mandate urgent evaluation. Avoid the trap of ordering advanced imaging for uncomplicated axial low back pain without red flags; imaging findings correlate poorly with symptoms. A second trap is dismissing pain as “non-organic” when nociplastic mechanisms are real. Document the patient’s own goals.
Worked example: a 58-year-old with six months of burning feet and normal strength. Ask about diabetes, alcohol, B12, chemotherapy, and HIV; examine pinprick and vibration; use a neuropathic screen. This is neuropathic pain until proven otherwise, and treatment targets mechanism, not just a number.
Rule of thumb: treat the patient’s function and mechanism, not the image or the intensity score alone.