If the milk blockage is not unblocked it can lead to milk stagnation, causing breast pain, mastitis, breast abscess, etc. 1. Breast pain: A variety of reasons for the blockage of the mammary ducts, the milk can not be discharged out of the body, can be caused by the accumulation of milk. When not dredged in time, it causes a localized hard knot in the breast, accompanied by swelling and pain. 2. Mastitis: The blockage of milk caused by milk stagnation, milk is a good culture base for bacteria, bacteria along the nipple rupture or lymphatic infection of the breast, resulting in acute mastitis, localized redness, swelling, heat, pain and other symptoms, but also high fever, chills and other symptoms. 3. Breast abscesses: When the milk blockage caused by mastitis is not dredged up in time and anti-infective treatment is given, the breast lump area will be necrotic and liquefied, resulting in breast abscesses. A superficial breast abscess can ulcerate outwardly, and a deep breast abscess can go inwardly to the loose tissue behind the breast, leading to a post-milk abscess. When breastfeeding women have breast ducts that are not clear and lead to milk stagnation, they should seek prompt medical attention and be given reasonable treatment under the guidance of a doctor, and should not be delayed to lead to serious adverse consequences.