Menstrual cycle, blood pressure and ischemic pain sensitivity in women: a preliminary investigation.

Eleven women were tested twice for ischemic pain sensitivity; once during their follicular phase (Days 4-9) and once during their mid-late luteal phase (5-10 days after ovulation) of a confirmed ovulatory cycle. Additionally, in order to examine blood pressure-related hypoalgesic effects, each had 3-4 clinic blood pressures determined during an initial screening interview and each also completed a daily symptom calendar for one complete menstrual cycle prior to testing in order to investigate relationships between 'real life' symptomatology and laboratory-induced pain sensitivity. Results revealed significantly shorter pain tolerance times and marginally shorter pain threshold times in the luteal vs. follicular phase, while verbal descriptors of pain intensity (sensory) and pain unpleasantness (affective) did not vary with cycle phase. Clinic blood pressures were positively correlated with pain threshold and tolerance times assessed during both cycle phases. Real-life physical symptom ratings were predictive of laboratory pain intensity ratings during the follicular phase and tended to predict unpleasantness ratings during both phases. These results not only confirm recent reports of greater sensitivity to ischemic pain in women during the luteal phase of their cycle, but extend the literature by demonstrating pressure-related hypoalgesic effects in women during both cycle phases.