Lymph nodes have good mobility under normal circumstances, and they are normal anatomical structures of the body as relay stations for lymphatic fluid return. Lymph nodes are usually abundant in the head, face, neck and perineum. If bacterial or viral infections of the surrounding tissues and organs occur, lymphadenitis in the head and neck or inguinal area may be caused, which manifests itself as enlarged lymph nodes, and may be accompanied by localized pain. Lymphadenitis is usually soft and mobile, and the enlarged lymph nodes may shrink or even disappear after anti-infective or anti-viral treatment. What needs to be alerted is that if the lymph nodes on the surface of the body are enlarged, accompanied by hard texture and not easy to move, it is necessary to be on high alert for metastatic cancer of lymph nodes. Lymphatic metastasis is a relatively common metastatic pathway in malignant tumors, for example, thyroid gland has peripheral lymph node metastasis, and generally papillary or follicular carcinoma can be detected in early stage of metastasis. Breast can also metastasize to the axilla and develop axillary lymph node metastasis. Usually, for lymph nodes with hard texture and poor mobility on the surface of the body, cytocentesis or even lymph node biopsy is needed to exclude the possibility of metastatic cancer.