The fever of unknown origin (FUO) is a medical phenomenon that presents numerous challenges and remains a difficult condition to manage despite advances in diagnostics. Fever, as a protective response of the body, can accompany various diseases, but in many cases, uncovering the underlying causes is not a straightforward task. Determining the cause of fever is not only a medical challenge but also a significant source of concern for patients and their families. Increasingly, we encounter febrile conditions where establishing a diagnosis can take months. A precise understanding of FUO is essential for appropriate treatment. The degree and duration of fever are key factors that must be thoroughly examined. During…