(FUO)- An extensive history and physical examination often will establish potential clues for the diagnosis of FUO.- Key elements of this history include establishing the fever itself, exposure history, prodromes, dietary history, travel history, military service, and detailed medical history including prior surgeries, implanted devices and transfusions, and all prescribed and over-the-counter medications and supplements. - Symptoms may be subtly present. The review of symptoms should be detailed and should be taken on repeated occasions, as symptoms may change or the patient may note their presence only on repeated questioning. - The initial panel of laboratory testing should be reviewed in detail, again looking for subtle clues that can guide further diagnostic work-up. A clinical microbiologist should be informed of infections you are searching for, so that special specimen collection or laboratory procedures can be employed. Radiologic imaging and nuclear medicine studies can have important roles in localizing pathology. Serologic testing has an important role in the diagnosis of both rheumatologic disorders and many infectious diseases with nonspecific symptomology. - When a diagnosis is not established after exhaustive searches, specialists can help in suggesting further diagnoses or recommending whether therapeutic trials are appropriate.*159/348/5*