Circadian Rhythms Part 1 – What Are They?

circadian rhythms

Why You Don’t Want To Mess Up Your Circadian Rhythm and Sleep

Our lives became so busy, and sleep became less important than passing an exam or working a night shift. And well, it is on you to choose how to live your life.

However, not all people know that living the nightlife can mess you up, leaving you confused, exhausted, and probably sick.

This is because we, and most other creatures on earth, have a unique biological system that keeps our body in sync with day and night cycles; it is our circadian rhythms ! 

Unlike the alarm clock, circadian rhythms don’t have a snooze button.

Our internal circadian rhythm and sleep is naturally synchronized to the sun’s rising and setting. Many of our organs are calibrated to the disappearance and appearance of natural light.

Therefore, messing with our circadian rhythm and sleep is like messing with the whole body!

What Exactly Are The Circadian Rhythms?

The term circadian comes from the Latin word circa (meaning around) and diēm (meaning day). 

Circadian rhythms affect eating, sleeping, and even mating.

The primary regulator of our circadian rhythms is a group of cells called the suprachiasmatic nucleus (SCN). 

This structure is a part of another structure called the hypothalamus, located in the brain.

The SCN is connected to the optic nerve, allowing the SCN to respond to light and dark. 

For instance, when you wake up in the morning, the optic nerve senses light, leading to the activation of the SCN.

 Consequently, the SCN sends signals to almost every organ leading to multiple effects like raising the body temperature, heart rate, blood pressure, promoting alertness, and delaying the release of melatonin (the sleep hormone).

Our memory, concentration, and alertness are at their maximum in the morning. This is why we tend to do best cognitively in the morning.

In the evening, as the sun disappears, the SCN notices these signals of dark and organs start shifting to low-gear, our blood pressure falls, temperature reduced, and the sleep hormone, melatonin, is produced.

Working and studying for late nights can damage this master clock that has been fighting to keep us in sync which can impact our circadian rhythm and sleep.

Why You Shouldn’t Mess Up With Your Circadian Rhythm Sleep Cycle

Scientists found that messing with this system can lead to insomnia, daytime sleepiness, and reduced productivity. 

Unfortunately, the issue with circadian rhythm and sleep abnormalities can be more complex than that.

Many studies have found that abnormal circadian rhythms can lead to serious abnormalities. 

They include:

1- Diabetes

2- Hypertension

3- Heart diseases

4- Sexual dysfunction and low testosterone levels

5- Dementia

6- Obesity

7- Mood swings

8- Poor mental health

Screentime & The Circadian Mess

Within the last 10 years, everything has become digital. Even a simple task like reading a book now can be done via an electronic device. 

Although tech is great and results in substantial improvement in our lives, it comes with drawbacks, too.

Studies found that the human eye is sensitive to the blue light produced by electronic devices (like pads, cell phones, and laptops).

When we are exposed to blue light, this can suppress melatonin production, causing a shift in circadian rhythm and sleep.

In fact, a research study found that participants using iPads before sleep took 10 minutes longer to fall asleep, experienced a less deep sleep, and took longer to feel fully awake the next morning, compared to people who didn’t use the iPad.


Listen, the science of circadian rhythm and sleep is a complex topic that even scientists don’t completely understand.

 Why lousy sleep habits can lead to the problems mentioned above? Why do we need to sleep at all? 

Perhaps because sleep is our deepest state of regeneration and recovery, but there are many questions about sleep that have no answers yet.

The only thing we are 100% sure about is that we need to sleep, and sleep deprivation and circadian rhythm abnormalities can lead to long-term health problems like obesity, diabetes, and sexual dysfunction.

Have you ever experienced circadian rhythm misalignment? Let us know in the comments below how you felt during this time and how you could combat that!

And if you are someone with brand-new insomnia, make sure to check out part two of this article series, where we give you actionable tips on how to get back to your natural rhythm!


1- https://www.ncbi.nlm.nih.gov/books/NBK526136/#:~:text=Chronic%20insomnia%20can%20adversely%20affect,irritability%20and%20increase%20daytime%20sleepiness.

2- https://www.ncbi.nlm.nih.gov/books/NBK519507/

Read More

5 Health Tips for Insomnia

The Surprising Connection Between Sleep and Heart Health

Healthy lifestyle habits with Dr. Steele

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