Cystic nodules in both breasts are first considered as breast cysts, which are benign tumors, mostly due to cystic hyperplasia of the breast, accompanied by changes in the menstrual cycle. If there is no obvious enlargement and no uncomfortable symptoms, you can follow up with ultrasound for observation, there is a small chance of malignancy, and if necessary, choose surgery to remove. Rarely, cysts are caused by the accumulation of breast milk, due to the blockage of breast ducts during breastfeeding, resulting in poor milk drainage and the formation of cysts with local swelling and painful symptoms, which can be eliminated through lactation treatment and breast duct drainage. If bacterial invasion easily leads to infection, acute mastitis will be formed, and in severe cases, abscesses will be formed, requiring oral antibiotics, and in severe cases, surgery, depending on the specific treatment of each case. Regardless of the type of cyst, it is recommended to follow up and observe with ultrasound, and if abnormalities are found, surgical treatment is recommended as much as possible.