Lymph can be removed, but in general, lymph node infection caused by local surrounding bacterial and viral infection can shrink or even disappear after anti-infection or antiviral treatment. If the lymph node metastasis is caused by tumor metastasis, lymph node dissection is needed, such as in the common clinical cases of gastric cancer, intestinal cancer, breast cancer and thyroid cancer, which will be accompanied by the surrounding lymph node metastasis. Because among malignant tumors, lymphatic metastasis is the earliest and the main metastatic pathway of malignant tumors. Therefore, when performing radical treatment of gastric cancer, radical treatment of intestinal cancer, radical treatment of breast cancer and radical treatment of thyroid cancer, the surrounding lymph nodes should be completely removed so as to achieve the purpose of radical treatment. For most of the lymph node infections caused by bacterial and viral infections, lymph node dissection is not required.