Cystic hyperplasia of the breast is one of the most common and prevalent diseases in women, mostly seen in women aged 25 to 45 years. Its pathology is diverse and its name is not uniform. Western scholars mostly call it “fibrocystic mastopathy”; in China, cystic changes are rare and glandular hyperplasia is the main cause, so it is mostly called “mastoproliferative disease”. The World Health Organization (WHO) collectively calls it “benign breast dysplasia”. Because the risk of malignant change is 2-4 times higher than that of normal women, clinical symptoms and signs are sometimes confused with breast cancer, so it is important to understand the correct concept and management measures. Etiology: The etiology and pathogenesis of this disease are still not well understood. At present, it is mostly thought to be related to endocrine disorders and psychological factors. The decrease of luteinizing hormone secretion and the relative increase of estrogen are the important causes of this disease. The main pathology: benign hyperplasia of the interstitial mammary glands, hyperplasia can occur around the ducts and accompanied by the formation of cysts of varying sizes; can also occur in the ducts and epithelial papillary hyperplasia, accompanied by cystic expansion of the milk ducts. In addition, there is also a type of lobular parenchymal hyperplasia. Clinical manifestations: The prominent manifestations are breast swelling and pain and intramammary lumps. (a) Breast distention and pain: It is common to have unilateral or bilateral breast distention and pain or tenderness. The duration of the disease varies from 2 months to several years, and most patients are characterized by cyclic pain, which occurs or worsens in the premenstrual period and decreases or disappears after menstruation. It must be noted that although the cyclical nature of breast pain is typical of the disease, the lack of this feature does not negate the presence of the lesion. (B) Breast lumps: they are often multiple, unilateral or bilateral, mostly in the upper quadrant; and their size and texture often change periodically with menstruation, with the lumps increasing in size and hardness in the premenstrual period and shrinking in size and hardness after menstruation. On examination, the lump can be palpated as a nodal structure, varying in size, with unclear boundaries with the surrounding tissues, mostly painful to touch, without adhesions to the skin and deep tissues, and can be pushed, and the axillary lymph nodes are not enlarged. In addition, there is also a long course of disease, slow development, and sometimes nipple overflow and other manifestations. The nodules of different sizes in the breast are essentially some large and small cystic dilated milk ducts, and the nipple overflow is from these cysts, which are yellow-green, brown or bloody, and occasionally colorless plasma. Diagnosis: According to the above clinical manifestations and signs, it is not difficult to diagnose this disease. However, it should be noted that malignancy can occur in a small number of patients (about 2-3%); therefore, attention should be paid to the follow-up observation of suspected patients, which is usually reviewed every three months. Unilateral and limited lesions should be especially vigilant. Treatment: Since there is no exact understanding of the mechanism and cause of the disease, the current treatment is basically symptomatic. Some patients can often resolve on their own after several months to 1 to 2 years after the onset of the disease and do not require treatment. For patients with more obvious symptoms and more extensive lesions, a bra can be used to support the breast; oral administration of Xiaojin Dan 6-9 grams twice a day, or Xiao Yao San 3-9 grams three times a day, or 5% potassium iodide 5 ml three times a day can relieve the symptoms. In recent years, there are more similar drug products, such as breast lump elimination, breast fetish elimination, asparagine tablets, flat elimination tablets, cystic fetish spirit, triamcinolone, etc., with different treatment effects. In the follow-up observation of patients, once a lump with rapid growth or hardening texture within a short period of time is found, the possibility of cancer should be highly suspected, and if necessary, biopsy or simple excision of the affected breast should be performed, and if cancer cells are found in the frozen section during surgery, it should be treated as breast cancer. Some people use androgens to treat this disease in order to suppress the effect of estrogen, soften the nodules and reduce the symptoms; however, this treatment may aggravate the imbalance between human hormones and should not be applied routinely. It should only be considered when the symptoms are severe and affect normal work and life. Dosage: Oral methyltestosterone, 5 mg each time, three times daily within one week before menstruation; or intramuscular testosterone propionate, 25 mg daily for 3 to 4 days.