Lymph nodes in the neck are generally small, about 0.5 cm. Generally, the lymph nodes behind the ear can be touched on the surface of the body because of the thin subcutaneous fat, and the surface of the lymph nodes is smooth, with clear borders and very good mobility, and there is no pain when the lymph nodes are pressed. If the lymph nodes are enlarged with pain, it may be considered to be caused by inflammation, and oral antibiotics, such as cefixime or cefradine, are needed for treatment. If painless lymph node enlargement occurs and the enlarged lymph nodes can be palpated on the body surface or detected by ultrasound in the neck, it is usually indicated to be caused by tumor metastasis, and further examination is needed to find the primary lesion of the tumor, and if necessary, radical tumor surgery.