Lymph node pus is not always caused by cancer, the most common is inflammation, that is, infectious diseases, mostly seen in local or regional soft tissue infections, and the other is lymphadenitis or dengue, the most common causative agent is streptococcus, the patient will show local pain, redness and swelling, and fever. If lymphadenitis is not treated in time and effectively, the condition will gradually evolve into suppurative lymphadenitis, and the patient will also have increased fever and increased blood tests. In this case, we should choose timely surgery for incision and drainage, and after the operation, we should actively change the medicine and intravenous anti-infection treatment. For patients with advanced malignant tumors, especially the emergence of multiple lymph node metastases, also prone to secondary lymphadenitis or suppuration, the patient will have obvious fatigue, anemia, loss of appetite and weight loss.