A group of three lymphatic metastases of breast cancer, i.e., three metastases of the breast tumor to the lymph, indicates that the disease is more serious, and metastasis usually occurs in the late stage of breast cancer. Lymphatic metastasis of breast cancer is relatively common and belongs to common localized metastasis. Cancer cells can be transferred to ipsilateral axillary lymph nodes from primary foci along lymphatic vessels, and the blockage of major lymphatic vessels can cause upper limb edema due to the obstruction of upper arm lymphatic reflux. Compression of the axillary vein or nerves by enlarged lymph nodes may cause purple swelling of the upper extremity or pain and discomfort in the upper arm. Supraclavicular lymph node metastasis can be secondary to axillary lymph node metastasis or directly from the primary site. If supraclavicular lymph node metastasis occurs, the cancer cells may invade the vein through the thoracic duct or the right side of the neck lymph node, causing blood vessel metastasis. It is recommended that patients facing such situations should undergo medical examination and timely follow-up to prevent further deterioration of the condition. Patients suffering from the above mentioned symptoms should consult the doctor in time to clarify the specific cause of the disease and carry out treatment according to the doctor’s prescription.