90 - Pain: Sex/Gender Differences

Abstract

The issue of how sex and gender differences influence pain continues to be a focus of intense investigation at many levels of inquiry. Epidemiological studies consistently report a higher prevalence of chronic pain disorders in females in comparison to males. Indeed, very few persistent pain conditions show a higher male prevalence. Psychophysically, women will generally rate a stimulus as being noxious at a lower intensity level than males; however, there are many exceptions to this generalization, with individual and situational variations being greater than the sex differences. On the other hand, substantial sex and gender differences do appear to exist in the mechanisms by which pain is generated and relayed centrally. The many factors that underlie sex differences in pain mechanisms interact dynamically, and develop and change progressively throughout the life span of each individual. Sex differences in the actions of the gonadal steroids estradiol, progesterone, and testosterone have also been shown to contribute to these differences, affecting wide regions of the central and peripheral nervous system. However, despite their potency, gonadal steroids represent only one of many factors that influence the experience of pain. While these differences would appear to have potent clinical implications for the development of different strategies to diagnose and treat pain in women and men, it remains the case that such strategies are most effective when they are focused on the individual, with the sex of that individual being only one of many factors being considered.