Women’s breast swelling and pain, the specific causes are as follows: a. Physiological factors 1, puberty: adolescent breasts begin to develop, there is a slight swelling and pain. 2, before menstruation: premenstrual body estrogen levels increase, breast hyperplasia, interstitial tissue edema and other causes of breast swelling and pain. 3, after pregnancy: about 40 days after pregnancy, due to the placental villi secrete a lot of estrogen, progesterone, prolactin, etc., so that the mammary gland hyperplasia, due to breast enlargement 4.Postpartum: 3-7 days after childbirth, lymphatic retention, venous filling and interstitial edema of the mammary glands and poor ducts. 5.After abortion: After abortion, due to the sudden interruption of pregnancy, the hormone level in the body drops sharply, causing the newly developed mammary glands to suddenly stop growing, resulting in breast lumps and breast pain. Pathological factors 1. mastopathy: due to endocrine hormone imbalance, and breast tissue is more sensitive to hormone response. 2. mastitis: common acute mastitis occurs mostly in lactating women, especially in primiparous women due to bacterial infection. 3. breast cancer: when tumor is accompanied by inflammation, there can be swelling and pain or pressure pain, and in late stage, if tumor invades nerve or axillary lymph node compression, or invades brachial plexus nerve, there can be Shoulder swelling and pain.