Definition and clinical manifestations of breast milk cyst: breast milk cyst, also known as lactic stasis, is a gland lobe during lactation due to poor milk discharge, resulting in the accumulation of milk in the breast and become, the main clinical manifestation is the breast mass, often misdiagnosed as a breast tumor. Because of the swelling of the breast during the breastfeeding period, the lump is not easy to be detected, and often can be clearly detected only after weaning. Cysts are round or ovoid, smooth surface, can be pushed, most of them are unilateral, single cysts, there may be slight pressure pain, touch may have cystic sensation. The diameter of the cyst is often 2-3 centimeters, usually no axillary lymph node enlargement, young women in breastfeeding or after the discovery of breast boundary clearer swelling, check in the areola area outside the more marginal parts of the border touch clear, activity, surface smooth swelling, should think of cumulus cysts of the possibility of hospital with the help of breast ultrasound can be diagnosed, and should pay attention to breast cysticercosis, mammary gland adenofibroblastic tumors, breast cancer to differentiate. Pathogenesis: Breast cyst is rare in clinic, its formation is related to pregnancy and breastfeeding, during lactation, if one or more milk ducts are not discharged properly or blockage occurs, causing milk stagnation and formation of cysts, the contents of which are different from general cysts because of the milk or cheese-like material. To the naked eye, lactation cysts are grayish-white, can be unicompartmental or multicompartmental, and contain milk or cheese-like material. Clinical patients are mostly women under 40 years old who used to breastfeed, and most of them are found in 1-5 years after delivery. Treatment: A few breast cysts can be spontaneously absorbed and dissipated, if the breast cyst is not infected, it can exist for a long time, the contents of the cyst will become thicker, and with the passage of time, it can absorb the water in the cyst, which will make the cyst harden. Treatment of breast cysts is mainly based on western medical treatment, including non-surgical treatment and surgical treatment. Non-surgical treatment: 1, puncture aspiration: when performing needle aspiration cytology of the mass, if milk-like fluid is aspirated, the milk in the capsule should be sucked out at one time. When the milk is sucked out, the cyst is seen to shrink, and the residual cyst cavity is then bandaged with pressure, and in a few cases, a one-time suction can be cured. 2, if the cysts recurring, repeated puncture is ineffective can consider surgery. Surgical treatment If the cyst has repeated inflammatory infections or keeps growing, simple cyst removal can be performed under local anesthesia. This is a benign lesion, only simple cyst removal can be performed, without the need to remove the mammary gland. If accompanied by acute inflammation, anti-inflammatory treatment before surgery. In case of breastfeeding, the operation should be performed after the return of breast milk. Preventive measures: 1. Develop regular breastfeeding habits to avoid milk retention in the mammary glands due to non-emptying of the milk. 2. Pay attention to the hygiene and posture during breastfeeding to avoid stagnation of milk due to poor drainage of the milk ducts, which may lead to infection. 3, pay attention to the postnatal diet, avoid eating spicy and stimulating food, eat more light, high protein content food. At the same time, you should learn to adjust and keep your mood relaxed, so that you can keep away from the pain of the disease.