Low density shadow of two ribs one year after breast cancer surgery may be caused by breast cancer bone metastasis and osteoporosis. 1. Breast cancer bone metastasis: as a malignant tumor, breast cancer has the risk of distant metastasis, and if it metastasizes to the ribs, it will damage the ribs, which will be manifested as localized bone hypodensity during examination. Some patients will have the symptom of pain. 2. Osteoporosis: due to age increase, long-term endocrine drugs, insufficient diet and other reasons, breast cancer patients will lead to calcium loss, which will further lead to osteoporosis and low density of ribs. One year after breast cancer surgery, multiple low density of ribs, accompanied by obvious pain and discomfort symptoms, need to consult a doctor in time for examination, and carry out standardized treatment under the guidance of clinicians after diagnosis of the disease, so as to avoid the delay of the disease.