What is a Fever?


A fever is a temporary increase in your body temperature, often due to an illness, like the flu. It’s part of your body’s defense system, as a slight fever activates your body’s immune system, making it harder for the bacteria and viruses that cause the infections to survive.  If you have a fever, it’s a pretty good bet that something out of the ordinary is going on with your body.

What are the symptoms of a fever?

You have a fever when your internal body temperature rises above the normal 98.6°F (37°C). Additional fever symptoms may include:

  • Sweating
  • Shivering
  • Headache
  • Muscle aches
  • Loss of appetite
  • Dehydration
  • General weakness

What causes a fever?

Fever or elevated body temperature might be caused by:

  • A virus, like the flu
  • A bacterial infection
  • Heat exhaustion
  • Extreme sunburn
  • Certain inflammatory conditions such as rheumatoid arthritis — inflammation of the lining of your joints (synovium)
  • A malignant tumor
  • Some medications, such as antibiotics and drugs used to treat high blood pressure or seizures
  • Some immunizations, such as the diphtheria, tetanus and acellular pertussis (DTaP), or pneumococcal vaccine

Is a fever serious?

Woman checking her temperature

Fevers generally go away on their own after a few days. However, if you’ve had a fever for more than 3 days, or if your temperature rises above 103° F (39.4° C), contact your doctor. If a high fever is left unchecked, it may cause hallucinations, confusion, and/or convulsions.

How do you treat a fever?

As always, when you're sick, you should drink plenty of fluids, get lots of rest, and in the case of a fever, try to stay as cool as possible.

For a low grade fever, it’s often best to do nothing and let it run its course. In the case of a high-grade fever, you can take aspirin, acetaminophen, or ibuprofen. NeoCitran Ultra Strength Total Flu contains 1000 mg of acetaminophen to reduce fever.

If you need to see a doctor, you might be prescribed an antibiotic.