Swollen lymph nodes are very common and can occur in people of any age, and can be seen in a variety of diseases, both benign and malignant. There are 3 common types of enlarged lymph nodes: 1. Benign enlargement. These include enlargement caused by various infections, connective tissue diseases and allergic reactions. They are often clinically benign and can recover completely in a certain period of time with the removal of the cause. 2. Malignant enlargement. It includes malignant tumors originating from lymph nodes, such as lymphoma, lymphocytic leukemia and malignant histiocytosis, and lymph node metastases from other malignant tumors, such as lung cancer, gastric cancer and breast cancer. The lymph nodes are persistently and progressively enlarged, and if not actively treated, they often deteriorate and die. 3.The enlargement between benign and malignant. Such as vascular primitive immune cell lymphadenopathy and vascular follicular lymph node hyperplasia. They are often benign at the beginning and can become malignant and fatal. Therefore, after determining the enlarged lymph nodes, it is crucial to determine their causes and nature. Generally speaking, local enlargement with obvious pain often suggests infection; progressive painless enlargement often suggests malignant neoplastic disease, so it is very important to pay attention to the causes of enlarged lymph nodes and to seek timely diagnosis and confirmation to avoid misdiagnosis and omission. Bone marrow aspiration and immunohistochemistry or lymph node biopsy can help and exclude malignant tumors originating from lymph nodes. Since the opening of the Lymph Node Clinic of the Department of Hematology, it has provided a very favorable platform for diagnosing and excluding lymph node-related diseases, and the number of patients seen or consulted has gradually increased.