Menstrual characteristics of 2,343 women attending the Shepherd Foundation.

Menstrual characteristics of 2,343 women attending the Shepherd Foundation Health Testing Centre have been analyzed utilizing a computer system of data analysis. The incidence of menstrual pain was 43% and premenstrual tension 75%. The best estimate of normal cycle length was 21-35 days, 1.5% of women having cycles less than 21 days. The duration of menstrual loss was 1-7 days, 3% of women bleeding for more than 7 days. Utilizing the various responses to questions concerning menstrual and cycle length, menstrual pain and premenstrual tension, 150 patterns were found, the 10 most common patterns accounting for 40% of the population; most of the latter patterns included menstrual pain and premenstrual tension. Authorities disagree upon the definitions of normal menstruation and there are serious implications from the lack of knowledge in this area, both for the individual patient and the cost of health care. The formation of a health committee to determine national standards for defining normal menstruation is advocated.