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What Is Circadian Rhythm?

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Up to date
Update: November 15, 2022
3 min read

Written by

Sarah Shoen
Writer Editor
illustration of circadian rhythm

Circadian rhythm is our body’s internal clock that primarily responds to light and dark. The physical, behavioural, and mental changes follow a 24-hour cycle. The circadian rhythm’s main responsibility is regulating the sleep-wake cycle. And one of the best examples of circadian rhythm is that we sleep at night and feel active and energetic during the day. But there is more. This article will walk you through everything you must know about circadian rhythm and how it works. Read ahead! 

What is circadian rhythm? 

As aforementioned, circadian rhythm is our body’s internal 24-hour clock that regulates sleep and wakefulness. Our circadian rhythm is influenced by light and dark and various other factors. Based on your environment, your brain receives the signal, producing certain hormones and altering your body’s temperature. It also stimulates your metabolism to tell you if it is time to sleep or wake up. This is circadian rhythm meaning.

How Does Circadian Rhythm Work? 

Now, let’s take a look at how circadian rhythm works. There are various components that come together to form the circadian rhythm.

Circadian rhythm in babies

A newborn baby develops a circadian rhythm after its birth. As the baby turns 8 weeks old, the cortisol rhythm is developed. By 9 weeks, melatonin and sleep efficiency tend to make their way, and finally, the body temperature and circadian genes develop by 11 weeks. 

Circadian rhythm in teens

There is a shift in the circadian rhythm pre and post-puberty in teenagers. Before puberty, your body tends to make you sleepy by 8 to 9 PM. However, with puberty, the rhythm tends to shift a couple of hours, and you would feel sleepy by 10 or 11 PM. 

Circadian rhythm in adults

Adults usually enjoy a consistent circadian rhythm as long as they practice healthy sleep habits. Here, your sleep and wake-up should remain stable, and you must aim to achieve at least 7 to 9 hours of sleep every night. Usually, melatonin is released in the body before midnight, so you tend to feel sleepy around that time. However, circadian rhythm tends to change as you age. Older adults generally go to sleep earlier and wake up sooner than later.

Is a Circadian Rhythm the Same As a Biological Clock? 

No, circadian rhythm and a biological clock are not the same. Biological clocks are our body’s internal clock that manages various bodily processes, including circadian rhythm. Now, circadian rhythm is the byproduct of the biological clock. So, not all biological clocks can be categorized as circadian rhythms.

How do circadian rhythms affect health? 

Circadian rhythm is essential for your body to carry out various functions. The main one is maintaining good sleep patterns. It also helps regulate your hormones, body temperature, and eating habits. When your circadian rhythm doesn’t work as it is supposed to, it can adversely affect your health. It has been associated with several health issues, such as diabetes, depression, and obesity.

Factors that can change circadian rhythms 

A few factors that can change or affect the circadian rhythm include; 

  • Pregnancy 
  • Shift work 
  • Jet lag or changes in the time zones 
  • Medications 
  • Health disorders, such as Parkinson’s disease or Alzheimer’s 
  • Make a few changes in your daily routine, such as staying up late to work or read 
  • Menopause 
  • Mental health issues 

How To Maintain a Healthy Circadian Rhythm 

Now that you know all the factors that can change the circadian rhythm, let’s look at all the tips that will help you maintain it. 

Seek out the sun:

When you step out in the sunlight first thing in the morning, it helps strengthen your circadian cue. 

Follow a consistent sleep schedule:

This is a significant step in maintaining a healthy circadian rhythm, and that is to sleep and wake up at a consistent time. 

Get daily exercise:

Physical activity during the day can help reinforce your circadian rhythm and helps you easily fall asleep at night. 

Avoid caffeine:

While a cup of coffee can give you some much-needed energy in the morning, having it post 12 PM can hamper your sleep as coffee stays in your system for at least 10 hours.

Limit light before bed:

Light can interfere with your sleep. Therefore, it is important to keep the lights dim at night and avoid using any electronics at least an hour before bed. 

Keep naps short and early in the afternoon:

Long naps can push your bedtime and hamper your sleep schedule. Therefore, it is always important to keep afternoon naps very short. 

Following these steps can helps strengthen your circadian rhythm and ensure you enjoy a deep slumber at night.

When to Seek Doctor’s Help

You must talk to your doctor if;

  • You have been having trouble sleeping or have been sleeping poorly for more than a month now. 
  • You notice difficulty in concentrating, forgetfulness, and severe daytime sleepiness due to poor sleep quality. 
  • You feel tired even after a good night’s sleep.
  • You don’t feel fresh when you wake up.

Now you know everything there is to know about circadian rhythm. It is an important factor that helps regulate your sleep-wake cycle. Therefore, it is always wise to keep the circadian rhythm stable.


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Written by

Writer Editor
Sarah has covered news topics for digital and print publications. She has a degree in broadcast journalism from the University of Nevada.

Latest circadian rhythm
illustration of circadian rhythm
Update: November 15, 2022

  • 3 min read