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Circadian rhythms

Circadian rhythm's or 24-hour cycles are driven by the body's "biological clock." The "biological clock" is regulated by light or darkness, which can make the body think it is time to sleep or wake up.

The 24-hour circadian rhythm controls functions such as:

  • Sleeping and waking.
  • Body temperature.
  • The balance of body fluids.
  • The way other body systems function.
Author Jeannette Curtis
Author Caroline Rea, RN, BS, MS
Editor Susan Van Houten, RN, BSN, MBA
Associate Editor Pat Truman, MATC
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer Alfred Lewy, MD, PhD - Psychiatry
Last Updated August 8, 2008

WebMD Medical Reference from Healthwise

Last Updated: August 08, 2008
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