Assessment of Chronic Pain: Domains, Methods, and Mechanisms

•Pain assessment represents a critical component of chronic pain classification.•Multiple domains of pain should be assessed, including pain severity, pain qualities, bodily distribution of pain, and temporal characteristics of pain.•Methods for assessment of pain mechanisms should also be considered, including quantitative sensory testing, brain imaging, epidermal nerve fiber density, microneurography, and pharmacological phenotyping.

Accurate classification of chronic pain conditions requires reliable and valid pain assessment. Moreover, pain assessment serves several additional functions, including documenting the severity of the pain condition, tracking the longitudinal course of pain, and providing mechanistic information. Thorough pain assessment must address multiple domains of pain, including the sensory and affective qualities of pain, temporal dimensions of pain, and the location and bodily distribution of pain. Where possible, pain assessment should also incorporate methods to identify pathophysiological mechanisms underlying the pain. This article discusses assessment of chronic pain, including approaches available for assessing multiple pain domains and for addressing pathophysiological mechanisms. We conclude with recommendations for optimal pain assessment.PerspectivePain assessment is a critical prerequisite for accurate pain classification. This article describes important features of pain that should be assessed, and discusses methods that can be used to assess the features and identify pathophysiological mechanisms contributing to pain.