Breast swelling and pain may be physiological factors, but also may be the manifestation of certain diseases, such as breast cystic hyperplasia, mastitis, breast tumors, etc., should be timely consultation to identify the cause. 1. Physiological factors: breast gland growth: adolescent girls will be due to fluctuations in the level of hormones in the body, the growth of breast glands, at this time there will be obvious symptoms of swelling and pain, is a normal situation, do not need special treatment. Some women in the breastfeeding period will also appear breast swelling and pain, mainly related to the secretion of milk from the mammary glands, can be relieved by local massage. 2. Pathologic factors: (1) cystic hyperplasia of the breast: usually have the symptom of breast pain, there will also be breast hardness, mainly related to endocrine hormone disorders. (2) Mastitis: female mastitis can cause breast swelling and pain, usually associated with secondary bacterial infection during breastfeeding, often accompanied by localized elevated skin temperature of the breast, breast redness and swelling, as well as fever and other symptoms. (3) Breast tumor: Breast tumor can also cause breast swelling and pain, and you need to cooperate with your doctor to clarify the nature of the tumor. If breast swelling and pain occurs, you should consult the doctor in time, ask the doctor to clarify the specific cause, and if necessary, carry out the corresponding treatment.