Lateral breast pain is usually caused by breast enlargement, which usually occurs in young and middle-aged women. When the hormone level in the patient’s body is disordered, it will easily cause the hyperplasia of breast tissue, such as the imbalance of estrogen and progesterone, especially before and after menstruation, which is more obvious, often manifested as increased pain and swelling before menstruation, and the symptoms will be reduced or disappear after menstruation. In addition, for example, mastitis and breast cysts, which are common in women, can also cause pain on the outside of the breast or around it. If the pain is obvious and lasts for a long time, you can take oral Chinese medicine for treatment, such as Xiaojin pill, breast fetish elimination and Yi Yao pill, etc. If the pain is not obvious, it is recommended to pay attention to diet and not to wear tight underwear.