Originally, not only women but also men bloodied due to injuries were prohibited from entering sacred places, while hunting and other activities in sacred places were prohibited for the same reason; however, it seems that based on a characteristic of male chauvinist thinking in the feudal era, only the uncleanliness of blood during menstruation and puerperal period had been emphasized and used as the reason for the removal of women from sacred places.
本来は、女性だけでなく、生傷を負って流血している男性が神域に入ることや、神域での狩猟なども同様な理由で禁止されているのだが、封建時代の男尊女卑の風潮から、女性を神域から排除する理由として生理や産褥の血の穢れのみが強調され、使われはじめたと思われる。