The most typical symptom of breast enlargement is breast swelling and pain, which may be accompanied by lumps in the breast and nipple overflow, especially before the onset of the physiological period. The most common cause of mastitis is the accumulation of milk in breastfeeding women, which causes redness, swelling and pain in the breast. When a breast tumor is accompanied by inflammation, there will be painful swelling or pressure. The pain and swelling may be caused by breast development during adolescence and will gradually disappear when adolescence is over and development is mature. Five, there may also be postpartum or sexual life caused by breast pain, it is recommended to go to the hospital breast specialist for further examination.