Hormones
Progesterone and estrogen are two hormones that trigger the growth of the uterine lining. In general, fibroids contain more receptors of these hormones than other uterine muscle cells. Therefore, when women are in their menstrual cycles, uterine fibroids would be caused due to higher amounts of both progesterone and estrogen. The exact mechanism is still unclear and more researches are needed to explain why these elements affect the growths of uterine fibroids. [3]
