Swollen lymph nodes in the neck are usually caused by inflammation, viral infection and tumor. 1. Inflammation: Commonly, enlarged lymph nodes in the neck may be caused by inflammation, such as gingivitis, otitis media, bacterial pharyngitis, etc. When the local tissues are infected with inflammation, it may lead to enlarged lymph nodes. 2. Viral infections: Viral infections may also lead to swelling of lymph nodes in the neck, such as cytomegalovirus infection, EBV infection, etc., which may lead to swelling and pain in the lymph nodes in the neck. 3. Tumor: If the patient’s body temperature is normal and the symptom only manifests as swollen lymph nodes, it may be caused by tumor, such as stomach cancer, lung cancer, nasopharyngeal cancer, etc., which may lead to metastasis of malignant tumors, and it is suggested that the patient should go to the hospital for relevant examination to clarify the cause. Swelling of lymph nodes in the neck is also seen in other causes, and patients should consult doctor in time and standardize the treatment under the guidance of professional doctors to avoid delaying the condition.