There are many causes of swollen lymph nodes, including: 1. Infections Acute and chronic inflammation caused by pathogenic microorganisms, such as bacteria, viruses, rickettsiae, etc., such as acute cellulitis, purulent tonsillitis, gingivitis, infectious mononucleosis, scrub typhus, tuberculosis, etc. 2, tumors (1) lymphoma; (2) various types of acute and chronic leukemia; (3) plasma cell tumors: multiple myeloma, primary macroglobulinemia; (4) tumor metastasis: lung cancer, gastric cancer, liver cancer, breast cancer, nasopharyngeal cancer, etc. 3, reactive hyperplasia (1) necroproliferative lymphadenopathy; (2) serum sickness and serum sickness-like reaction; (3) allergic subsepticemia; (4) systemic lupus erythematosus rheumatism, etc. 4, abnormal cell proliferation metabolism (1) Langerhans histiocytosis (histiocytosis X); (2) lipid deposition disease; (3) nodular disease. Specific judgments need to be based on symptoms and specific conditions!