Enlargement of submandibular lymph nodes is mostly related to infectious factors and connective tissue diseases. Prolonged submandibular lymph node swelling does not disappear, may be chronic inflammation and malignant tumors caused by, such as chronic lymphadenitis, malignant lymphoma, etc., need to consult the doctor in a timely manner, improve the relevant examination, and the treatment of the cause. Chronic lymph node is caused by bacterial or viral infection, inflammatory factors and other local cell or tissue hyperplasia in lymph nodes. In addition to submandibular and cervical lymph node enlargement, it can also involve occipital, behind the ear and other lymph node enlargement, redness, swelling, pressure and pain and other symptoms when inflammation occurs. It is necessary to choose the appropriate medication according to the causative pathogen, and the treatment time is longer. If submandibular lymph node enlargement does not disappear for many years, connective tissue disease should be guarded against. A variety of connective tissue diseases can lead to jaw lymph node enlargement for a long time, such as systemic lupus erythematosus, tuberculosis and so on. You should go to the hospital and take the appropriate treatment according to the doctor’s prescription, such as taking prednisolone, interferon and other drugs. Lymphoma is a malignant tumor originated from lymph nodes and lymphatic tissues, the main manifestation is painless progressive lymph node enlargement, which can occur in the lymph nodes of the jaw, usually accompanied by fever, night sweats (sweating abnormally after going to sleep, and the sweating stops after waking up) and other symptoms. Treatment is mainly based on chemotherapy, bone marrow transplantation, and radiation therapy. The disease sometimes progresses slowly and can present with enlarged mandibular lymph nodes for many years. If the submandibular lymph nodes do not disappear for many years, the examination should be perfected, and the diagnosis should be clarified and the treatment should be timely and actively carried out, so as to avoid delaying the disease.