Axillary lymph nodes are lymph nodes located in the armpit, which are normal physiological structures of the human body, and there is no difference between benign and malignant lymph nodes in normal lymph nodes. When some causes lead to enlargement of axillary lymph nodes or other lesions, the initial distinction is mainly made by the texture, presence or absence of pain, and surface morphology of the lesioned lymph nodes, etc. PET-CT can also be used to help further diagnosis, and the gold standard for benign and malignant diagnosis is pathological biopsy.1. Benign tendency: the boundary between the lymph nodes and other surrounding tissues is clear, no adhesions are formed, easy to push, and the lymph nodes Benign lymph node enlargement is mostly caused by infections and other diseases, and there are usually foci of infection or trauma near the enlarged lymph nodes; 2. Malignant tendency: In malignant lymph node lesions, the lymph nodes are often adherent to the surrounding tissues, their position is fixed, they are not easy to be pushed, and their surface is not smooth and their shape is irregular. Early lymph node lesions are usually painless. In addition, some of the malignant lymph nodes are due to metastasis of the primary lesion, for example, breast cancer metastases to the ipsilateral axillary lymph nodes, and a painless node that cannot be easily pushed can often be felt on the upper part of the ipsilateral breast. Most of the abnormalities in axillary lymph nodes are due to inflammation caused by enlarged lymph nodes. This condition is usually benign and can be improved by anti-inflammatory treatment. If benign or malignant cannot be determined, it is recommended to seek medical treatment and have the cause clarified and treated by the doctor through examination.