Breast fibroids are common benign tumors of the breast, generally considered to be closely related to the active action of estrogen, and occurring during the period of active sexual function (18 to 25 years of age). It occurs in the outer quadrant of the breast and is solitary in about 75% of cases, with a few being multiple (simultaneous or not). Other than the presence of a lump, the patient usually has no significant primary symptoms. In breast fibroids, the lump is slow to increase in size; on examination, it is firm, with clear borders and smooth surface, and can be easily pushed. The menstrual cycle has no effect on the size of the lump. Fibroadenoma of the breast is the third most common breast disease after cystic hyperplasia and breast cancer; among benign tumors of the breast, fibroids and fibroadenomas account for about 3/4 of the total. Young women have vigorous ovarian function and their sex hormones are in active period. It is generally believed that the production of breast fibroids is related to the stimulation of estrogen. Since some people’s breast tissues are sensitive to estrogen, the epithelial and fibrous tissues of the breast will be stimulated by estrogen in different degrees, and we call them fibroids. Breast fibroids are mostly benign, usually solitary, but there are also multiple cases. Patients usually do not feel them because they are painless or have only a slight swelling or dull pain, and this pain and size are not related to the menstrual cycle. When combined with pregnancy or breastfeeding, the mass will increase significantly.