Periodic discharge, mainly of blood, from the womb, beginning between the age of 13 to 15 and lasting from 2 to 8 days. It recurs approximately every 28 days, ceasing during pregnancy and lactation, and continues until the age of 44 to 50 years. It causes considerable inconvenience, whether physical or through increase in tension. It may be associated with menstrual pains and headaches. It may provoke various forms of discrimination against the woman at that time, or be used to justify such discrimination at any time.
A number of cultures have prescribed strict adherence to ritual behaviour coordinated with the menstrual cycle. For instance, during the first few days of her menstrual period a Hindu woman may not mount a horse, an ox, or an elephant, or drive a vehicle; and many peasants of Central and Eastern Europe persist in the belief that a menstruating woman should not bake bread, churn butter, or spin thread. The Orthodox Jewish and Muslim cultures specify a number of restrictions on menstruating women; including sexual abstinence and separation from society.
In early Western cultures, menstruation was believed to render a woman periodically dangerous, and numerous and varied social restrictions were created to limit her contact with her husband and with members of her community. During the 19th century, it was the opinion of some physicians that menstruation had no purpose whatsoever and that, indeed, it was a pathological condition, which had not existed in pre-Biblical times. This concern about the dangers of menstrual blood prevailed until as late as 1945.
As an indication, the market for female sanitary protection (including female hygiene tampons and sanitary towels) in the UK in 1986 was £123 million.