Sex Differences in Pain and Its Treatment

Pain is a highly personal experience. Pain is often considered to be a purely neurologic phenomenon, but in actuality, it is a combination of both sensory and emotional experiences. This has sometimes been translated clinically toward a more mechanistic approach to the assessment and treatment of pain instead of one that does not discount pain mechanisms, but also is more inclusive of the need for humanism - considering the individual. In today's medical environment, more than ever before there is a significant amount of attention being paid to educating clinicians to better understand that several physiological, neurophysiological, and psychosocial factors can significantly impact responses to pain. The composition of these factors will be unique to that individual's life narrative, context, sex, and prior life experiences. Thus, the concept that a templated approach to pain assessment and pharmacotherapeutic treatment planning should not be expected to provide optimal patient satisfaction and treatment outcomes in the majority. The hypotheses that there may be sex-based differences in the pain experience in a variety of ways including pain sensitivity, tolerance to pain, threshold at which something becomes painful, and the effectiveness of endogenous pain modulation systems are not new and have been well represented in the literature. This chapter reviews important key findings in the scientific literature with respect to sex-based differences in pain and pain responses to experimentally induced painful stimuli, pain experienced in commonly occurring painful medical conditions, and variations in responses to pain treatments. Possible explanations to account for observed differences or similarities will also be discussed.