<unk>  <unk>  refers to a condition in which the patient has an elevated temperature (fever) but, despite investigations by a physician, no explanation has been found. If the cause is found it is usually a diagnosis of exclusion, that is, by eliminating all possibilities until only one explanation remains, and taking this as the correct one.
Fever of unknown origin
Q fever
Relapsing fever
Pontiac fever
Enterotoxemia
Cat Scratch Fever
Morning sickness
Streptococcal pharyngitis