The Uterus (womb or Baogong), located in the Lower abdomen behind the Bladder of women, is the most important of the six extraordinary Yang-viscera. This organ, shaped like an inverted pear, regulates menstruation and pregnancy.
A healthy girl, on reaching the age of about 14, will get her menarche. The onset of menstruation takes place once a month regularly, caused by the Qi and Blood of the viscera acting on the Uterus.
Pregnancy is a series of complex physiological activities, assisted by Xin 
, Gan 
, Pi 
, and Shen 
, as well as the Chong and Ren Meridians.
Fetal growth and development, as well as lactation, rely on abundant Qi and Blood. Gan, which dredges and disperses Qi, and stores and regulates Blood, and is crucial for healthy uterine function. The Uterus is closely related to Gan-Qi and Gan-Blood. Gan dysfunction will cause amenorrhea, menorrhagia, or metrorrhagia.