Cyclical fluctuation in response to cold pressor pain across the menstrual cycle

This study investigated possible cyclic fluctuations in pain sensitivity across the menstrual cycle. Subjects were eighteen females with normal menstrual cycles, eight females who use oral contraceptives and eighteen males. As well, females who reported being dysmenorrheic were compared to female who experience little or no pain with menstruation. Female subjects were tested once at each phase of the menstrual cycle (menstrual, follicular, ovulatory and luteal) on the cold pressor task. Male subjects were tested at four correspondingly spaced time intervals. Magnitude estimation procedures, whereby the subject gives pain reports relative to an original standard of experienced pain, were used to monitor pain growth. Tolerance measures to the cold water were also recorded. Analyses revealed no fluctuations in pain sensitivity across the four phases of the menstrual cycle. Females who use oral contraceptives did not differ in their responses to the painful stimuli from females who do not use the pill. Whether female subjects scored as dysmenorrheic or nondysmenorrheic also did not influence responses. Male subjects on the other hand, had significantly higher tolerances than both female groups. As well, the numerical values male subjects attached to their pain reports were significantly lower than the ones given by female subjects. However, males did not experience pain growth at a significantly different rate than females. Results are discussed in terms of previous research, and social/psychological variables in the experience of pain.