Pain: types, measurement and management

Pain is not simply tissue damage

Two people with identical injuries report very different pain, and phantom limb pain exists where there is no tissue at all. Pain is produced by the brain, not merely detected by it — which is why psychological techniques can change it.

Types

Acute pain has a clear cause and resolves; chronic pain persists beyond healing and is a condition in itself. Phantom limb pain is felt in a missing limb. Organic pain has an identifiable physical cause; psychogenic pain does not — but psychogenic does not mean imaginary, and saying so in an answer is a serious error.

Gate control theory

A 'gate' in the spinal cord regulates signals travelling to the brain. Small fibres carrying pain signals open the gate; large fibres carrying touch and pressure close it, which is why rubbing an injury helps. Signals descending from the brain — attention, anxiety, expectation, mood — also open or close it, and that is the mechanism behind distraction, relaxation and the placebo effect.

Measuring pain

Self-report: visual analogue and numerical rating scales are quick, and the McGill Pain Questionnaire captures the quality of pain through descriptive words. Behavioural observation (guarding, grimacing, limping) is useful for people who cannot self-report. For children, faces scales are used. Each has the same fundamental problem: pain is subjective, so all measures are indirect.

Management

Medical: analgesics, anaesthetics, surgery. Psychological: attention distraction, imagery, hypnosis, biofeedback, and cognitive strategies that change the meaning of the pain. The evaluation point is that psychological methods work best alongside medical treatment, not instead of it, and are especially valuable for chronic pain where medication carries long-term risks.