Milk pain means that breast pain may be caused by physiological reasons, breast hyperplasia, mastitis, breast trauma and other factors. 1. Physiological reasons: Adolescent women may cause breast pain when they have their first menstrual period, and when the milk is not emptied, it may also cause breast pain to occur in breastfeeding women. And pregnant women may also feel breast pain because of hormone level changes. 2. Mammary gland hyperplasia: When the estrogen and progesterone in a woman’s body are disturbed, it may also lead to hyperplasia of the lobes of the mammary glands, resulting in symptoms of breast pain. 3. Mastitis: If the milk is stagnant or the nipple is cracked, it will easily lead to bacterial invasion and mastitis, and when the mammary gland has an acute suppurative infection, it is easy to have symptoms of breast pain. 4. Mammary gland trauma: when the mammary gland is subjected to extrusion, impact and other traumatic injuries, the symptoms of breast pain may also occur. In addition, breast cancer, breast fibroadenoma, cardiothoracic disease may also appear similar symptoms, patients with breast pain should go to the hospital in time to improve the examination, to clarify the cause of the disease and follow the doctor’s instructions for treatment.