Most fevers are caused by pathogenic infections, and with these pathogenic infections, there is a possibility of immune system reactions, including swollen lymph nodes. Superficial lymph node enlargement is a common manifestation of many febrile diseases, such as rubella, where superficial lymph node enlargement is more likely to occur. In the case of scrub typhus, the superficial lymph nodes near the site of the scrub typhus bite may also be swollen to touch. Other diseases, such as fever with thrombocytopenia syndrome, may also present with enlarged superficial lymph nodes. In the case of the common cold, it is not too common, although it may also be present, so swollen lymph nodes can sometimes indicate some specific disease. In the case of infectious mononucleosis, in addition to fever, rash, and enlarged tonsils, superficial lymph nodes may also be enlarged throughout the body. In addition, if a tumor is accompanied by an infection or metastasis, lymphatic metastasis may also be present, and fever and lymph node enlargement may be seen at the same time. In addition, lymphoma and leukemia of the hematological system often present with swollen lymph nodes and fever, and require lymph node aspiration biopsy or bone marrow aspiration for diagnosis.