Fever in adults

Infection is a common cause of fever, but other conditions can also bring the heat.

Fever is one of the body's most effective ways of fighting infection.

The average body temperature is 98.6° F (37°C). But "normal" body temperature varies from person to person. It also changes during the day, rising a bit after you eat or exercise. Body temperature is often higher in the afternoon than it is when you wake up in the morning.

Fever means a body temperature of 100.4° F (38°C) or higher. An infection, such as the flu, is the most common cause of fever.

Other conditions can also cause a fever. These include diseases that produce inflammation, such as rheumatoid arthritis; reactions to drugs or vaccines; and even certain types of cancers.

Fever symptoms

People with a fever may also:

• sweat
• shiver (chills)
• have a headache
• have achy muscles
• not want to eat
• break out in a rash
• be restless
• feel weak.

A very high fever can cause confusion, extreme sleepiness, irritability, and seizures.

Diagnosing the cause of a fever

To help determine why you have a fever, your doctor will ask you about:

• other symptoms such as coughing, abdominal pain, vomiting, diarrhea, or pain when urinating
• recent surgeries or injuries
• recent vaccinations
• new drugs you may be taking
• recent travel, particularly travel abroad.

Treating a fever

Fever is part of your body's defense against infection-causing germs. By itself, fever is usually harmless, though a high fever can be miserable. These steps may help you feel better:

• Drink plenty of fluids to help cool your body and prevent dehydration.
• Eat light foods that are easy to digest.
• Get plenty of rest.
• Take ibuprofen (Advil, Motrin, or others), naproxen, (Aleve, Naprosyn, or others), acetaminophen (Tylenol, others) or aspirin to help relieve head and body aches and lower your temperature.
• Take a slightly warm, not cool, bath or apply damp washcloths to the forehead and wrists.
• Dress lightly (even if you have chills).

If you have a fever over 104°F (40°C) call your doctor. Call your doctor right away if you have a fever along with any of these symptoms:

• seizure
• loss of consciousness
• confusion
• stiff neck
• trouble breathing
• severe pain anywhere in the body
• swelling or inflammation of any part of the body
• vaginal discharge that is discolored or smells bad
• pain when urinating or urine that smells bad

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