The axillary lymph nodes are the lymph nodes in the lower part of the armpit. According to the distribution of lymph nodes, they can be divided into axillary apical group, central group, pectoral group, subscapular group and lateral group. When the axillary lymph nodes are enlarged, we should be alert to the possibility of tumor metastasis. If the tumor metastasis appears as painless lymph node enlargement, it is common for breast cancer to cause axillary lymph node metastasis. You should check your breast for lumps, and if necessary, you can do breast ultrasound or mammography, and also check your axillary lymph nodes. If enlarged lymph nodes are found, you should describe the number and location of the enlarged lymph nodes and whether they have fused into a mass. If it is confirmed to be caused by breast cancer, modified radical breast cancer surgery is required.