Lymph node enlargement often occurs when the human body has a cold or upper respiratory tract infection. The main reason is that when the human body is infected by bacteria or viruses, the lymphatic system reacts, and the lymphocytes that are generated will ingest the bacteria and viruses and cause reactive hyperplasia. In the patient’s body, the corresponding lymph nodes will be enlarged, especially in the neck and submandibular lymph nodes often appear, the upper respiratory tract cold symptoms are mostly due to the oral cavity, nasopharyngeal infection, so the nearby lymph nodes reactive hyperplasia is the most obvious, and the enlargement is relatively obvious, and often due to the symptoms of upper respiratory tract infections and colds and concomitant inflammation of the lymph nodes. The lymph nodes can be gradually restored to normal size through anti-inflammatory and antiviral treatments.