Cystic hyperplasia of the breast, also known as chronic cystic mastopathy, or mastopathy for short, is a benign hyperplasia of the breast parenchyma commonly seen in middle-aged women. Its clinical manifestations are sometimes easily confused with breast cancer, so it is important to understand this disease correctly. The prominent manifestations of this disease are breast swelling and pain and lumps, characterized by the cyclical nature of some patients. The pain is related to the menstrual cycle, often increasing before menstruation and decreasing or disappearing after menstruation, and sometimes throughout the menstrual cycle. Physical examination reveals diffuse thickening of one or both mammary glands, the thickened area is not clearly demarcated from the surrounding breast tissue, and a few patients may have nipple overflow. The disease has a long course and develops slowly. The possibility of malignancy is still debated, but there is a possibility of co-existence of breast cancer and this disease. For early detection of possible breast cancer, patients should be instructed to visit the hospital for review every 2-3 months. When a lump of limited mastopathy is obvious, it should be distinguished from breast cancer. The latter lump is more definite, hard in texture, more clearly distinguishable from the surrounding breast, and sometimes has enlarged axillary lymph nodes. This disease is mainly treated symptomatically and can be treated with Chinese herbal medicine or proprietary Chinese medicine. Commonly used medicines include Prosperity Pill and Nucleus Dissipation Pill. For limited cystic hyperplasia of the breast, it should be reviewed within 1 week to 10 days after menstruation. If the lump becomes softer, shrinks, or recedes, it can be observed and the medication can be continued. If the lump does not subside significantly, or if the local lesion is suspicious for malignant lesions during observation, it should be removed and a rapid pathological examination should be performed. If there is atypical epithelial hyperplasia, the scope of surgery can be decided in combination with other factors. If there are high-risk factors such as contralateral breast cancer or family history of breast cancer, as well as those who are older and also have more obvious hyperplasia of breast tissue around the lump, simple mastectomy can be performed. In the absence of these conditions, close follow-up after lumpectomy may be performed. This disease is an endocrine disorder hyperplasia. Firstly, the metabolic disorder of women in the body, especially the imbalance of estrogen and progesterone ratio, makes the breast parenchyma hyperplasia and incomplete replenishment. Secondly, the quality and quantity of female hormone receptors in some breast parenchyma components are abnormal, resulting in uneven degree of hyperplasia in various parts of the breast.