Circadian Rhythms

< Featured Topics

What Are Circadian Rhythms?

Circadian rhythms control the physical, mental, and behavioral changes an organism experiences over a 24-hour cycle. Almost all living things, from bacteria to humans, have circadian rhythms. They’re controlled by a biological clock, which is composed of proteins encoded by thousands of genes that switch on and off in a specific order in response to the daily cycle of day and night.

Read More >
A glowing green shape with red-and-blue streaks.  

Health Effects

Circadian rhythms can influence important body functions like hormone levels and temperature. The most noticeable effects of circadian rhythms are predictable sleep patterns. Traveling across several time zones or working the night shift can disrupt these sleep patterns and cause drowsiness, poor coordination, and difficulty staying focused.

Nobel Prize

In 2017, three NIGMS-supported researchers won the Nobel Prize for finding a gene in fruit flies that helps control circadian rhythms. Similar genes in the human body affect sleep patterns, sharpness of brain functions, and more.


NIGMS Biomedical Beat Blog promotion.  

Biomedical Beat blog posts related to circadian rhythms.

Learn More

NIGMS Educational Resources


Issue of Pathways student magazine focused on circadian rhythms (grades 6-12).

Learn More
A crescent moon next to words that read, The Science of Sleep.  

An interactive that explores different regions of the brain when someone is conscious, asleep, or unconscious.

Learn More

Other Resources

This page last updated on 12/11/2023 2:53 PM