The exact cause of uterine fibroids is not known, but several factors may play a role. According to the Mayo Clinic, these factors may include gene changes and hormones, specifically estrogen and progesterone, which cause the tissue that lines the inside of the uterus to thicken during each menstrual cycle
. The Cleveland Clinic also supports this, stating that the exact cause is unknown, but healthcare providers believe that hormones, especially estrogen and progesterone, play a role in the development of fibroids
. Additionally, research suggests that each tumor develops from an abnormal muscle cell in the uterus and multiplies rapidly when encountering the estrogen hormone, which promotes the tumor's growth
. The Office on Women's Health and the NHS also mention hormonal and genetic factors as potential causes of fibroids
