A 55-year-old woman’s breast swelling and pain may be breast trauma, mastitis, cystic hyperplasia of the breast, breast cancer, shingles, and so on. 1. Mammary gland trauma: breasts are squeezed, bruised, needled, burned and other traumas lead to local skin and subcutaneous tissue damage, thus breast swelling and pain. 2. Mastitis: Inflammatory lesions of the mammary gland due to nipple breakage, bacterial infection, etc. Inflammatory exudation increases, so the breasts will be swollen and painful. 3. Breast cystic hyperplasia: excessive proliferation of breast glandular ducts and glandular epithelial tissue leads to the expansion of breast lobules and ducts to form cysts, which can lead to the formation of breast lumps and slight pain. 4. Breast cancer: cancerous proliferation of breast epithelial cells causes the formation of breast lumps, nipple discharge, breast pain and other symptoms. 5. Herpes zoster: Herpes zoster of the breast skin will appear as a pimple on the skin of the breast area, accompanied by pain, and occasionally the patient may feel itchy. Breast swelling and pain may be related to a variety of factors, it is recommended to consult a doctor to clarify the diagnosis.