The reason for the swelling of the chest is as follows: 1, puberty development, both boys and girls puberty body hormone levels are unstable, breast tissue may develop a feeling of swelling, after puberty will disappear. 2, endocrine disorders, such as pre-menstrual and menstrual period estrogen content increased, will appear chest swelling pain performance. If the symptoms are not obvious, you do not need to treat it, but if the pain is obvious, you need to take masturbation or Chinese medicine to regulate the endocrine secretion. 3, mastitis, because of breast duct deformity or refusal to breastfeed, resulting in the accumulation of milk in the breast swelling and pain. If pus appears, you need to wear a negative pressure drain for drainage after surgery, and then remove it when the drainage flow is small.