As eager as you were to nestle right into bed after your 10-hour flight, your brain is simply not having an inclination to sleep. Perhaps your Sunday night feels like high noon, and you can’t quite convince your brain that it is actually time for bed. Well, if you happened to guess that your circadian rhythm, also known as your sleep clock, is responsible, you are on the money. 

Your circadian rhythm is a psychological clock established by your brain’s recognition of light and dark environments. The brain’s exposure to illuminated and dimmed settings will have an impact on your circadian rhythm by convincing your brain that patterns and habits it perceives through its sensory have changed. Your brain does not distinguish types of ambient light, so it will regard both warm sunlight and an artificially illuminated area with white LEDs as daylight. The color of light helps mitigate changes to your circadian rhythm, although when you are exposed to ambient light overall, it becomes the main adjustment of the rhythm itself. 

What does this mean for sleep? Well, if your circadian rhythm is well adjusted to your time zone, then you’ll hardly notice any irregularities. Sleep should be regular and consistent. Once you notice a difficulty to wind down during a normal bedtime, or if you perceive time as being later or earlier than usual, your circadian rhythm is likely off and may prevent you from sleeping during your normal, warranted bedtime.

What Is Circadian Rhythm?

A circadian rhythm is the internal clock established by your brain. Your brain will make note of when it is exposed to light and when it is exposed to darkness, creating a loose 24-hour clock to go by. The clockwork is quite fragile since, biologically, your brain has only been exposed to two variables to adjust it: sunlight and moonlight. Now, we have phone screens, televisions and even light fixtures that can easily influence our circadian rhythm. 

As far as research goes, these are the primary factors that can adjust your circadian rhythm:

  • Light and its gradients: Red-colored light affects your circadian rhythm the least, while blue lights affect it the most.
  • Field of view: The more the field of view is occupied by light, the more drastic the effects will be on your circadian rhythm.

How Does Circadian Rhythm Work?

In the previous section, we mentioned the two primary variables for adjusting your circadian rhythm being light and field of view. Your hypothalamus, the portion of your brain responsible for the input from your eyes, responds to a group of neurons regarded as the suprachiasmatic nucleus (SCN). Your SCN will then determine what genes to prepare and encourage cells to work hard during wakefulness. It will also determine which genes to reduce or diminish entirely, so rest may occur. The genes play a role in reinforcing, resupplying and fortifying rest for cells. When you are awake, genes will begin to empower the neural network for wakefulness. When you sleep, this network is less of a priority, so your body focuses on your neural network to promote rest. 

Your exposure to ambient light will affect which genes behave accordingly. If you are watching TV at 2 a.m., but your bedtime is 10 p.m., your hypothalamus will interpret the ambient light as daylight and, thus, telling your body to continue to support the neural network for wakefulness. In doing so, the later you remain awake and exposed to ambient light, the earlier your brain perceives it to be.

How Does Circadian Rhythm Affect Sleep?

Your circadian rhythm affects sleep by adjusting to prolonged exposure, or absence, of ambient light during periods when light or darkness is usually not present. For example, if you had flown into a time zone six hours behind, your body will be adjusted to the time zone you normally rest in and not the new one. Despite your conscious regard for the time zone you are currently in, your body is instead adjusted to previously established exposure of ambient light and darkness, therefore impacting the hour at which you should be drowsy or even asleep.  

Your circadian rhythm may have negative impacts on your sleep if you are accustomed to a different periodic schedule for wakefulness and somnolence. If your circadian rhythm becomes grossly adjusted, you may find yourself sleeping at odd hours or even having difficulty sleeping as it is.

How To Maintain a Healthy Circadian Rhythm?

Your circadian rhythm may absolutely be restored and adjusted to a more agreeable, functional clockwork for your lifestyle. Adjusting your circadian rhythm begins with waking up at the same time every day. Sounds simple, right? It truly is that simple of a step. When you regularly awake at the same hour, despite how late you slept, your body will always try to be ahead of you and wake you up. Maintain this, and you will begin to align your circadian rhythm to your lifestyle.

Another step to maintaining a healthy circadian rhythm is light therapy. Light therapy is an intense approach and requires a physician practicing sleep medicine. With this approach, your physician will orient you to regard light and darkness at different periods of the day. This practice helps with graveyard shift workers, so its effectiveness is quite reputable.

A final step to consider is sleep-assisting medication or supplements, like melatonin or valerian root. Melatonin is naturally produced in your body when your brain perceives night-time approaching. Melatonin activates a pathway in your brain that induces tiredness. Valerian root follows the same pathway although has less odds of interfering with deep sleep cycles like melatonin does. You are recommended to consult your primary physician, or sleep medicine physician for more insight.

How To Reset Circadian Rhythms

If you’ve disrupted your circadian rhythm and are having trouble sleeping, we have good news! You can reset your sleep cycle and get the rest you need through a variety of means.

  • Take melatonin supplements: Melatonin is a chemical that already exists naturally in your body. This hormone is what helps you associate a decrease in light as the time to rest and an increase in light as the time to be awake. Unfortunately, melatonin decreases with age. Melatonin supplements can help you re-establish your circadian rhythm if you take them right before bed.
  • Establish consistent, healthy sleep habits: If your circadian rhythm has been disrupted, chances are you don’t have consistent and healthy sleep habits. You can remedy this by going to bed and waking up at the same time every day. Over time, your body will adjust to your new sleep schedule and re-establish your circadian rhythm.
  • Food and caffeine: As delicious as caffeine-infused drinks are, try to curb your intake at least several hours before you go to bed. Caffeine can take up to five hours to leave your body so curb your intake much earlier in the day. Also, be sure to have consistent meal times throughout the day as studies show this can also throw off your circadian rhythm.
  • Bright Light Therapy: Bright light therapy, or chronotherapy, can help with your sleep since lighting is strongly tied to how we rest. Consult with your physician on what the best course of action is for you, but you do not need a prescription to purchase a light therapy box. Set up your light near where you work or sit and let the light do it’s work. Be consistent when you choose to utilize light therapy. 

Final Thoughts

As enjoyable as it is to stay up late watching TV or playing video games, your body’s inner clock intuitively knows what is required to get the rest you need. Fortunately, if your circadian rhythm does get thrown off — perhaps you are traveling or took a late shift at work — there are lots of ways to re-establish it and get settled into a consistent period of sleep. Consider utilizing light therapy, melatonin, and establishing sleep habits to reset your brain and get the rest you need. Consult with your doctor if you’re having trouble establishing a regular sleep pattern as you may have a circadian rhythm sleep disorder.