Pain in the infant: theoretical and conceptual issues.

Existing theories of pain are individually inadequate to explain pain in infants. There is limited understanding of how the physiological response to pain (nociception) relates to the cognitive and behavioral response of infants. Little knowledge exists on how the context in which pain is experienced affects physiological and behavioral responses. Lack of a clear conceptualization of pain in infants has implications for nursing practice and research, most notably in the area of pain assessment and management. Several theories must be considered to address the complexity and multidimensionality of pain in infants.