Common breast cysts include simple cysts and cumulus cysts. Simple cysts are the most common among breast cysts. They are mainly due to endocrine disorders that cause ductal epithelial proliferation and increase of cells in the ducts, resulting in extension, tortuosity and folding of the ducts, and necrosis of the duct walls at the folded areas due to ischemia, resulting in cysts. Cysts are also known as milk retention cysts, which are less common than simple cysts and are mainly due to blockage of a duct during lactation, resulting in the formation of cysts due to milk stasis. For breast cysts, the most definitive diagnosis is a mammogram. Whether it is an anechoic nodule, whether there are attached tumors within the cyst, and whether there are irregularities and abundant blood flow in the cyst wall. The chance of malignancy in cysts is very small, but in most of them there are attached tumors, etc., or if the patient is under great stress, surgery can be considered. Surgical treatment is divided into open surgery or minimally invasive. For young patients, cyst excision surgery is performed, and if economic conditions allow, minimally invasive surgery such as McMurdoctomy is more effective: on the one hand, most of the cyst wall can be removed to prevent the formation of cysts again; on the other hand, the surgical scar can be largely ignored. In some places, cysts are still treated by needle aspiration, which is undesirable; because the cyst wall has a secretory function, the cyst will grow again soon if the cyst fluid is aspirated without destroying the cyst wall; moreover, repeated aspiration is likely to form infection and cyst separation.