What causes a fever?

A fever has many causes and can be a symptom of almost any illness. Among the most common are:

However, if you or your child are experiencing a higher-than-normal body temperature and no other symptoms of illness, don’t assume something is wrong. A person's body temperature changes throughout the day and varies with many normal activities and emotions.

For example, stress, excitement, heavy clothing, food, certain medications, a menstrual cycle and exercise can all raise body temperature. Also, children tend to have a slightly higher body temperature than adults.

Last reviewed by a Cleveland Clinic medical professional on 12/31/2019.


  • American Academy of Family Physicians. Fever. Accessed 1/6/2020.
  • Hague R. Managing the child with a fever. Practitioner. 2015;259(1784):17-21, 2-3.
  • NHS Choices. Fever in children. Accessed 1/6/2020.
  • Merck Manual. Fever. Accessed 1/6/2020.

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