Lymph nodes are found in every part of the body and are spread throughout the body, like the blood system and the nervous system, from head to toe. Generally speaking, lymph nodes are relatively small on the body and cannot be easily touched, but the lymph nodes behind the ears in the neck can sometimes be touched because of the thin subcutaneous fat, and are usually small, about the size of a soybean. Lymph nodes in the inguinal region are sometimes palpable on the surface of the body and are relatively large, the size of a soybean or a broad bean. If the lymph nodes become infected and painful, they are usually red and swollen and require oral antibiotics for symptomatic treatment. If the lymph nodes are swollen and there is no pain, the possibility of metastatic tumor is usually very high, and the lymph nodes need to be biopsied and sent to the pathology department for examination.