Smooth, tough, spherical masses in the breast are one of the characteristics of breast fibroids. It is a slow-growing, spherical or ovoid mass with smooth surface, firm texture, clear borders, and a sliding sensation when touched. It is common in young women aged 20 to 25 years old, mostly solitary, slow-growing, and may have no conscious symptoms, but often found unintentionally in spherical masses in the breast. The occurrence of this disease is related to the over-stimulation of estrogen, so it is most often seen in women aged 20 to 25 years old during their sexual vigor. During pregnancy, lactation or pre-menopause, tumors can grow rapidly due to the secretion of large amounts of estrogen; animal experiments have also confirmed that large amounts of estrogen can induce tumor formation. The specific causes of breast fibroids are as follows. 1.Lifestyle: Diet, radiation, medical treatment and lifestyle are also one of the causes of breast fibroids, such as vegetables, fruits, yams, mushrooms, soy products, carrots and green tea, which can reduce the chance of incidence. If women often drink alcohol or increase total fat intake, especially postmenopausal women are obese, it may also increase the incidence. 2, genetic inheritance: the first generation of relatives (mothers, sisters, etc.), if there is breast fibroid disease, this family may be at high risk of developing the disease, it is now found that if the patient’s blood or tissue contains the BRCA-1 gene, and at the same time, if the BRCA-1 gene can also be found in her children, then her children are in a relatively high risk state, but this does not mean that the disease is heredity. 3. Congenital factors: The abnormally high sensitivity of fibroblasts to estrogen in the lobules of the breast may be due to the high number of estrogen receptors contained in these fibroblasts. 4.The production of mammary fibroids is related to the stimulation of estrogen: Since some people’s breast tissues are more sensitive to estrogen, the epithelial and fibrous tissues of the mammary glands will undergo different degrees of hyperplasia due to the stimulation of estrogen. 5. Endocrine factors: Breast fibroids are related to reproduction or endocrine factors. The occurrence of breast fibroids in the following groups is 1.3-3 times higher than normal, such as those with age of menarche less than 12 years old or age of menopause more than 55 years old; high estrogen level or estrogen replacement therapy after menopause, age of birth of first child more than 35 years old or no birth, no breastfeeding after delivery; short menstrual cycle, which indicates a long duration of estrogen action.