Breast cancer bone metastasis and frozen shoulder can be judged by the symptoms, lesion sites, causes and relevant examinations. Bone metastasis of breast cancer is considered to be caused by the development of breast cancer to middle and late stages, and the cancer cells metastasize to the bone, which is most common in the chest, lumbar vertebrae and pelvis, followed by the ribs and femur. It mainly manifests as bone pain, pathologic fracture, spinal nerve root compression and so on. The diagnosis should be confirmed by mammography, breast ultrasound, tumor marker test and breast MRI. Frozen shoulder is considered to be caused by degenerative changes in the shoulder joint and its soft tissues, which may be caused by prolonged inactivity, leading to joint stiffness. Symptoms of frozen shoulder are mainly pain around the shoulder joint and limitation of movement. With the development of the disease, some patients may also be accompanied by a fear of cold in the shoulder, fear of cold wind, and applicable muscle atrophy in the shoulder muscles. This phenomenon needs to be diagnosed through physical examination, X-ray examination, ultrasound and arthrography and other relevant examinations. Breast cancer patients should seek medical treatment in time to identify the cause of the disease.