Fever (also known as pyrexia or febrile response) is one of the most common medical signs and is characterized by an elevation of body temperature above the normal range of due to an increase in the temperature regulatory set-point. This increase in set-point triggers increased muscle tone and chills.
As a person's temperature increases, there is, in general, a feeling of cold despite an increase in body temperature
Some reasons for a fever are:
- infections, including pneumonia, colds, flu, ear infections, and bronchitis
- recent immunization (children)
- teething in children
- certain inflammatory diseases or autoimmune disorders, including rheumatoid arthritis and Crohn’s disease
- cancer
- blood clots
- certain medicines
