Local lymph nodes, also known as sentinel lymph nodes, are the first level of lymph nodes that direct lymph flow to an organ or site. Enlarged lymph nodes that can be palpated in superficial areas of the body include the armpits, neck, and groin. Localized enlarged lymph nodes found on examination are usually indicative of inflammation and tumors. Therefore, abnormalities in local lymph nodes can reflect lesions in their drainage areas, which is important for the diagnosis and treatment of certain diseases. When an organ is infected or cancerous, bacteria, viruses, parasites or cancer cells can reach the corresponding local lymph nodes along the lymphatic vessels, and the lymph nodes proliferate, producing a large number of lymphocytes to filter and kill the pathogens, and preventing the distant foci from being damaged by the pathogens. When the pathogenicity of the pathogen is too strong or the function of the lymph nodes is low, the local lymph nodes can not prevent the spread of the lesion, then the lesion can be connected to the lymphatic channels to spread to the distant places, and the local lymph nodes can be enlarged at this time. For lymph node enlargement caused by infection, its texture is relatively soft, and the patient may experience pain and other symptoms. However, if the local lymph node enlargement is caused by malignant tumors, its texture is usually hard, and it may cause pressure on the surrounding blood vessels, nerves and organs, and its mobility is poor. The examination found local lymph node enlargement, should attract attention, by the doctor for judgment, if necessary, targeted treatment.