Fever of unknown origin

A fever of unknown origin is a temperature that reaches 101°F (38.3°C) on and off for at least 3 weeks with no known cause. Fever is a symptom of another condition, so your doctor will do tests to narrow down the causes and determine how to treat the underlying illness.

Your doctor may prefer not to give you medication while your fever remains undiagnosed. Research suggests that fever helps fight infection. Treating the fever without knowing the cause might reduce your body's ability to deal with the possible infection. However, doctors will prescribe drugs to reduce fever in children who suffer seizures caused by fever (febrile seizures). Because a higher temperature increases your need for oxygen, your doctor may prescribe fever-reducing medicines if you have heart or lung problems.

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Review Date: 4/1/2016  

Reviewed By: Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.

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