Menstrual cycle modulation of tender points.

Changes in pain sensitivity throughout the menstrual cycle were assessed in 36 normally menstruating women and 30 users of oral contraceptives. Pain sensitivity was measured with palpation of rheumatological tender points and with pressure dolorimetry. The number of tender points identified by palpation was greater in the follicular (postmenstrual) phase of the cycle as compared to the luteal (intermenstrual) phase in normally cycling women but not in users of oral contraceptives. These findings are related to previously described physiological and psychological features of the menstrual cycle, with particular emphasis on the role of hormonal events in modulating pain perception, particularly in musculoskeletal disorders such as fibromyalgia.