Dandruff does not cause swollen lymph nodes in the neck. Common causes of enlarged lymph nodes in the neck include infections, tumors, and rheumatic immune diseases. 1. Infection: When the body is infected, the lymph nodes in the neck may swell due to immune response, common bacterial infection and viral infection. Bacterial and viral infections are common. For example, upper respiratory tract infections, oral gingivitis, etc. may cause swollen lymph nodes in the neck. After the inflammation subsides, the enlarged lymph nodes will recover. 2. Tumor: Some primary tumors can lead to enlarged lymph nodes in the neck, such as lymphoma. Metastasis of other malignant tumors can also cause enlarged lymph nodes in the neck, such as nasopharyngeal cancer, oral cancer metastasized to the lymph nodes in the neck, gastric cancer metastasized to the supraclavicular lymph nodes and so on. 3. Rheumatic and immune diseases: Suffering from certain rheumatic and immune diseases may also cause enlarged cervical lymph nodes, such as systemic lupus erythematosus, rheumatoid arthritis and so on. If you have enlarged lymph nodes in the neck, it is recommended to go to the regular hospital to find out the cause of the disease in time to avoid delaying the condition.