The normal diameter of the lymph nodes in the neck is about 0.2 to 0.5 cm, with soft texture, smooth surface and no pressure pain. Superficial lymph nodes in the neck are sub-chin lymph nodes, submandibular lymph nodes, anterior cervical lymph nodes, posterior cervical lymph nodes, and supraclavicular lymph nodes. Lymph nodes are not easily palpable under normal conditions. Lymph nodes are enlarged when they are >0.5 cm in diameter, or when there is tenderness and a change in texture that makes them palpable. Changes in the lymph nodes are closely related to the development and treatment of many diseases. When the lymph nodes are enlarged, infection, allergy, connective tissue disease (e.g., dry syndrome, systemic lupus erythematosus, etc.), hematological disease (leukemia, lymphoma, etc.), and lymphatic metastasis of malignant tumors may occur. When you find enlarged lymph nodes, it is recommended that you go to the hospital in time to complete the relevant examinations, so as to avoid delaying your condition.