You are here: 

What is the circadian rhythm?

The circadian rhythm is the body’s internal clock. It is a built-in biological rhythm, a rough 24-hour cycle that regulates certain physiological processes such as sleeping and eating.

This 24-hour clock inside your body tells you when you’re sleepy or hungry and helps control other physiological processes. The circadian rhythm rises and falls throughout the day and responds to environmental cues like sunlight. It’s why you’re mostly sleepy at night and awake during the day.

If you have a job or schedule that disrupts your circadian rhythm – for example, it forces you to be awake at night and asleep during the day or if you work shifts that frequently change the times you’re asleep and awake – it’s hard on your body and may increase your risk of health concerns, including cancer.

Learn more about how shift work can affect your health and your risk of cancer.

Explore related articles

Am I at a greater risk of cancer if I do shift work?

Tips to reduce your risk from shift work

Continue reading