Aches, Pain, Fever (cont.)

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What causes a fever?

Fever is the result of an immune response by your body to a foreign invader. These foreign invaders include viruses, bacteria, fungi, drugs, or other toxins.

These foreign invaders are considered fever-producing substances (called pyrogens), which trigger the body's immune response. Pyrogens tell the hypothalamus to increase the temperature set point in order to help the body fight off the infection.

Fever is a common symptom of most infections. In children, immunizations or teething in may cause low-grade fever.Autoimmune disorders, medication reactions, seizures, or cancer may also cause fevers.

What are the signs and symptoms of a fever?

A fever can cause you to feel very uncomfortable. Signs and symptoms of a fever include the following:

  • Temperature greater than 100.4 F (38 C) in adults and children
  • Shivering, shaking, chills
  • Aching muscles and joints
  • Headache
  • Intermittent sweats
  • Rapid heart rate and/or palpitations
  • Skin flushing
  • Feeling faint, dizzy, or lightheaded
  • Weakness
  • With very high temperature (> 104 F/40 C), convulsions, hallucination, or confusion is possible. Seek medical attention.

How is a fever diagnosed?

Along with having the generalized symptoms of a fever, taking your temperature with a thermometer can confirm the diagnosis of a fever. A temperature greater than 100.4 F in adults or children is considered a fever.

Medically Reviewed by a Doctor on 6/27/2014

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