Abstract
Purpose of this study was to examine whether premenstrual symptoms of teenage women and women in their early twenties include symptoms that are caused by abdominal pain or not. Prospective ratings of 238 menstrual cycles, collected from 109 Japanese college students, were analyzed. Any cycle with symptoms was classified as to whether they were accompanied by abdominal cramps or not. Each group was factor analyzed in order to examine the characteristics. For the No Cramps Group, the characteristics were similar to those of original 'premenstrual syndrome (PMS)'. For the Cramps Group, the characteristics of this group were that even though the symptoms started to be evident in the premenstrual period, they continue and build toward a peak during the menstrual phase. By regression analysis, it was clarified that the characteristics of this group were brought on by the abdominal pain. The characteristics of this group were incompatible with the typical definition of PMS. Therefore, the authors have proposed a new concept, which is 'peri-menstrual syndrome, (PEMS)' and accordingly, in this study PEMS is taken as meaning: 'Mental and social symptoms which, make their appearance in the premenstrual phase, continue and peak in the menstrual phase and disappear at the end of menstruation, are caused as a result of menstrual cramps'.
