Fever occurs when the body temperature exceeds 98.9 degrees Fahrenheit. If a temperature is taken during the evening hours, the number that constitutes fever moves up to 99.9 degrees Fahrenheit since the body tends to have a higher natural temperature at night.
Temperature is most often taken orally, although it may be taken rectally in children. Although some people take the temperature by inserting a thermometer under the arm, this method is not nearly as reliable as oral temperature.
Infections of viral, bacterial, or fungal nature often result in fever. People who have the flu often have a fever, especially at the onset of the illness. Other possible causes of fever include pneumonia, bronchitis, mononucleosis, urinary tract infection, and many other causes. Some people develop a brief fever for no clear reason, but fevers of that type will usually dissipate very quickly.
Fever is a symptom of an illness, rather than being its own distinct disease. Therefore, the aim of fever treatment is to discover why the fever occurred and treat the root cause of the problem. Many people experience self-limiting fever, for example, a viral infection that clears up and takes the fever away with it. Sometimes the fever symptom is treated with drugs like acetaminophen, which can bring the fever down quickly.
People with fever need to see the doctor if the fever persists for more than a few days. If the fever is accompanied by any other symptoms, for example, a rash, patients should see the doctor immediately. If the fever is over 100 degrees Fahrenheit, it is best to contact the doctor to discuss whether treatment is necessary.