Breast cancer can spread to the lungs. Breast cancer is a malignant tumor formed by uncontrolled proliferation of breast epithelial tissues under the action of various cancer-causing factors, such as hormones, heredity, radiation, and spirituality, etc. The main clinical manifestations of the patients are breast lumps, changes in the breast skin, and nipple overflow, etc. Breast cancer can spread through bloodstream. Breast cancer can spread through the bloodstream, and the cancer cells can directly invade into the bloodstream and metastasize to distant places, and the common ones are lung metastasis and so on. Breast cancer can spread to the lungs, mostly manifested as nodules of different sizes in the lungs. When lung metastasis occurs, it can be detected by imaging examination and symptoms such as fever, cough, sputum, dyspnea and so on appear, which affects the quality of life of patients. When breast cancer metastasizes to lung tissue, the condition is more serious and requires further adjuvant treatment, as well as local radiotherapy for the lung metastatic lesions, in order to improve the therapeutic effect and prolong the patient’s survival period. Generally speaking, through early detection, early diagnosis and early treatment, breast cancer can improve the prognosis of the disease and reduce its spread. It is recommended that patients should undergo regular treatment in time, and at the same time, patients with breast cancer should follow up and review regularly to prevent the disease from deteriorating and spreading.