The common causes and clinical manifestations of swollen lymph nodes in the neck are as follows: 1. Infection: such as oral ulcers, tonsillitis, inflammation of the head and face, and tuberculosis infection can cause swollen lymph nodes in the neck. The lymph nodes are swollen and painful, with smooth and pushable surfaces. With the elimination of inflammation, the lymph nodes in the neck will gradually dissipate and return to normal; 2. Tumors: can cause swollen lymph nodes in the neck, mostly due to tumors of other organs metastasizing through lymph nodes. Lymph nodes are hard, not easy to push, and not painful to touch. As the lymph nodes keep increasing, they can compress the surrounding skin, blood vessels and nerves, causing a series of symptoms. For example, compression of blood vessels in the neck may cause obstruction of blood flow to the head and face, resulting in swelling of the head and face; compression of the recurrent laryngeal nerve may cause hoarseness, etc. Treatment mainly targets the primary focus, and the enlarged lymph nodes can be shrunk through chemotherapy and radiotherapy.