Normal breasts will not have hard lumps when touched. Diseases are related to breast hyperplasia, breast fibroids, breast tumors and other factors. Breasts are mainly composed of glands and fat, such as hard lumps inside the breast, consider that it is caused by breast hyperplasia, with the increase in hormone levels will stimulate the breast follicles and interlobular mesenchymal stroma, resulting in the formation of localized nodules or obvious lumps. Hard lumps in the breast can also be considered to be caused by breast fibroids, which can be formed by changes in hormone levels and poor diet. Often eat high-fat food will lead to changes in intestinal flora, bile steroids in the colon will be converted to estrogen, so that the body more and more estrogen, hormone stimulation of the breast duct epithelium will cause lumps in the breast. Breast tumor can not be excluded, early breast tumor will not have obvious symptoms, but when you touch the breast with your hand, you will feel a hard lump in the breast.