Skip to content
Know.itKnow.it
Create an animated lesson
On request

This article is free to read. Creating a lesson uses your daily or stored credits; review the language and settings before starting.

How do circadian rhythms work?

ScienceLesson on requestFree to read

Quick answer

Circadian rhythms are your body's internal 24-hour clock. A region of the brain tracks light and dark and releases hormones — like melatonin at night — to control sleep, alertness, temperature, and more, keeping your body in sync with the day.

Step by step

  1. It's the body's roughly 24-hour internal clock.
  2. The brain uses light cues to keep time.
  3. Hormones like melatonin signal sleep and wake.
  4. It governs sleep, alertness, and body temperature.

People also ask

How do circadian rhythms work?
A brain clock tracks light and releases hormones to time sleep, alertness, and other daily body cycles.
What controls our circadian rhythm?
A brain region (the suprachiasmatic nucleus) syncing to light, which adjusts hormones like melatonin.
Why does jet lag happen?
Travel shifts your day faster than your internal clock can adjust, leaving rhythms out of sync.

Part of the guide: How Your Body Works →