The mammary glands of newborns should not be squeezed to avoid damage or even secondary infection and other adverse consequences. Because in the uterus, the mother’s estrogen, progesterone through the placenta into the fetal body, so after birth due to hormonal stimulation, will lead to the phenomenon of newborn mammary gland enlargement, which is a normal physiological phenomenon, do not need special intervention treatment, most of the 1 ~ 2 weeks will subside on their own. If the enlarged mammary glands are squeezed, it will lead to local soft tissue damage and edema, and in serious cases, it will lead to bacterial infection and even cause sepsis and other serious complications. Therefore, when a newborn baby has an enlarged mammary gland, it is important to take the baby to the pediatrics or neonatology department of the hospital in a timely manner to clarify the specific cause and give appropriate intervention care.