Breasts and sex hormones are inextricably linked, and sex hormones are vital to breast development and health. 1. Development: Sex hormones refer to gonadotropins, which generally secrete numerous hormones such as androgens, estrogens and progesterone, and are the main driving force for breast development. The growth and development of breasts need to rely on the coordination of a variety of sex hormones in the body. For example, during puberty, estrogen secreted by the ovaries promotes the overall development of breasts; during lactation, estrogen, under the synergistic effect of other hormones, promotes the development and production of breast milk. 2. Health: Sex hormones are involved in all aspects of body metabolism. If there is a lack or decrease of sex hormones in the body, it will not support the normal metabolic function of the body, especially on the breast health, if in the developmental period, the breast will stop growing and developing; if it is an adult woman, it is easy to lead to mammary gland diseases. In addition, sex hormones are also associated with certain diseases of the breast, such as breast hyperplasia and breast cancer.