Uterine fibroids are common benign tumors of female genitalia, and their exact etiology is not yet known. The reasons for the occurrence of uterine fibroids may be that the fibroid tissues are hypersensitive to estrogen, the promotion effect of progesterone and the cytogenetic abnormality of fibroids. 1. Fibroid tissue is highly sensitive to estrogen: biochemical test confirms that the estrone conversion of estradiol in uterine fibroids is significantly lower than that in normal muscle tissue, and the concentration of estrogen receptor in fibroids is significantly higher than that in peripheral fibroid tissue. Therefore, the high sensitivity of the fibroid tissue to estrogen may be an important factor in the development of leiomyoma. 2. The promotion effect of progesterone: some studies have proved that progesterone can promote the mitosis of leiomyosarcoma and stimulate the growth of leiomyosarcoma. 3. Fibroid cytogenetic abnormality: cytogenetic study shows that 25%-50% of uterine fibroids have cytogenetic abnormality. The occurrence of uterine fibroids may be related to many factors, female friends who suffer from uterine fibroids must give appropriate treatment under the guidance of doctors as soon as possible, and usually pay attention to the regular examination, and if there are abnormal vaginal bleeding, abdominal pain and other symptoms, they should also seek medical treatment as soon as possible.