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Circadian rhythm refers to the mental, behavioral, and physical changes regularly occurring during 24-hour cycles. Read more about the circadian rhythm at Meri Sehat.

Circadian Rhythms - A Top-Notch Health Concern

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Madeeha Syed

This article or video has been vetted and verified by Meri Sehat’s specialists. It contains citations and research from validated sources.

Are You Sleeping On Your Sleep Cycle?

Overview

The circadian rhythm is the internal biological clock that regulates the sleeping-and-waking time of every person. This rhythm is controlled based on the sleep-wake cycle, which is also called the light-dark cycle, and it&rsquo;s present in almost all life forms.&nbsp;

Additionally, the circadian rhythm is related to many physiological processes like mood, metabolism, body temperature, hormone secretion and more. Therefore, having a good sleep and waking up at the right time has many health benefits for all people.

The circadian rhythm refers to the physical and mental changes that occur within an organism throughout an approximately 24-hour cycle. This cycle is controlled by signals sent from various parts of the brain to control functions like body temperature, hormone secretion and more. 
&nbsp;

Circadian Rhythm

When you don&rsquo;t sleep enough or at appropriate times during the day (for example: staying up late on weekdays), this can throw off your circadian rhythm&nbsp; and affect your energy levels during waking hours too!

You may be asking yourself, why is sleeping on time so important? Well, there are many reasons for this. First of all, sleeping has a lot of benefits for the body and mind.

<ul>
	<li>Sleep As A&nbsp;Time For The Body To Rejuvenate: When you sleep your brain stops sending signals to your muscles and organs telling them what to do. This allows them to rest and recover from the day&rsquo;s activities. 
	&nbsp;</li>
	<li>Sleep As A&nbsp;Time For The Mind To Relax: While you&rsquo;re asleep, you don&rsquo;t think about anything or anyone else but yourself and your own needs. This can help reduce stress levels when done consistently with other relaxation methods (such as meditation). 
	&nbsp;</li>
	<li>Importance Of Sleep In Children: Children need at least 10 hours of sleep each night because they still have developing brains which require proper rest in order to grow properly into young adults who will eventually be able to function independently without assistance from parents or guardians. 
	&nbsp;</li>
</ul>

The first sleep is probably the most important part of the entire sleep cycle because it helps people fall asleep faster and have a longer rest throughout the night.&nbsp;

If a person doesn&rsquo;t get enough sleep during the first part of the night, that can have consequences during daytime as well. Some people may be more prone to falling asleep faster with two separate sleeps instead of one long one. This phenomenon is called &ldquo;first sleep&rdquo; or &ldquo;second wind&rdquo; and it occurs in humans as well as other organisms including fruit flies, rats and mice. 
&nbsp;

Lack of sleep can lead to a variety of health problems. The following are some common ailments that have been linked to a lack of sleep:

<ul>
	<li>Headaches</li>
	<li><a href="https://merisehat.pk/disease/depression">Depression</a> and <a href="https://merisehat.pk/disease/anxiety">anxiety</a></li>
	<li>Weight gain and obesity (insulin resistance)</li>
	<li>Memory loss and cognitive impairment</li>
	<li><a href="https://merisehat.pk/disease/diabetes-type-1-and-2">Diabetes type II (pre-diabetes</a>)</li>
	<li>Heart disease 
	&nbsp;</li>
</ul>

Bottom Line

The Circadian Rhythm is an internal clock that tells your body when to sleep and when to wake up. Disrupting this clock may not seem to cause a lot of damage right now but overtime, the damage accumulates and starts showing up when it is too late.&nbsp;

The concept of beauty sleep is somewhat related to maintaining a good circadian rhythm. While you are sleep, your body takes this time to undo the daily damage done to your cells. In this case, the blood flow supplies the key nutrient to your exhausted cells. The same is the case with your other organs, they take the time to reset and repair.&nbsp; 
&nbsp;

Our body gets used to when we sleep so much that we immediately start feeling tired regardless of our hectic or slow day. Ignoring this signal causes your brain and body to work overtime during their off hours. Think of your own productivity levels when you have to work overtime in your office, you are just pushing yourself without energy to somehow get the work done and go back home as early as possible. Our bodies are no less than a machine that needs their time off in a timely manner.&nbsp;

Circadian rhythm is an important part of our life as it regulates our sleeping and waking time. If you want better health and well-being, make sure you have enough sleep at night and wake up on time in the morning. This will help your body recover from stress caused by work or school during daytime so that you can function better throughout the day.

Umna Salah

AL SHIFA CLINIC KARACHI

Syed Intisar Hussain

All About Circadian Rhythm

Introduction

One of the most fascinating things about being alive means you have all these senses to facilitate your growth and development. You&rsquo;re not just living in a limbo, are you? You are aware of your needs, of your surroundings; you can think, make decisions, eat, breathe, reproduce. Basically, you do more than just exist. And as much as you like to complain that &lsquo;there&rsquo;s not enough time&rsquo; for you to be able to do everything you want to do, each and every movement you make is guided by time, a special 24-hour innate clock that governs your bodily systems and ensures you don&rsquo;t over exert yourself.&nbsp;

&nbsp;

When you think you&rsquo;re procrastinating too much, you&rsquo;re actually comparing your productivity to someone else&rsquo;s and that&rsquo;s where you&rsquo;re doing yourself and your body a great disservice. Because this internal clock (called circadian rhythm) is unique to each person. It&rsquo;s a 24-hour cycle that helps you manage your sleep routine. That is, thanks to your circadian rhythm, you manage to sleep and wake up at roughly the same time every day and your body manages to perform all its functions duly. 
&nbsp;

The circadian rhythm varies because it&rsquo;s easily influenced by external factors. For instance, the degree of light and darkness in your environment wherein light equates to day, the time you need to be active; this stimulus makes your brain activate hormones that control your metabolism. You feel a change in your body temperature soon after you wake up, right? Or, alternatively, when it&rsquo;s night, doesn&rsquo;t your body get this sudden urge to rest? That&rsquo;s your circadian rhythm, too, sending you a message that you&rsquo;re exhausted and need a good night&rsquo;s sleep.

&nbsp;

So, if we have this built-in clock at our service all the time, literally, then what&rsquo;s stopping us from achieving it all? What&rsquo;s the catch here? It&rsquo;s known as circadian rhythm disturbance. Nearly 7-10% of people who have trouble sleeping are diagnosed with this condition<a href="#accordion">[5]</a>. In adolescents, in particular, the prevalence is nearly 7%. Again, this issue can develop due to environmental influences that cause sleep issues and, consequently, disturb the circadian rhythm. But they are environmental factors, which means you can control them. You can still be in control. You just need to adapt to your body&#39;s natural rhythm better by upholding healthy behaviors.

&nbsp;

How do you do that? Read on to find out. 
&nbsp;

Understanding Circadian Cycle & Its Effects

Your body&#39;s intrinsic 24-hour clock or circadian rhythm aids in maintaining a regular schedule for bodily functions. It is composed of 4 distinct biological rhythms in your body &ndash; namely, the cells in your body, hormones like cortisol and melatonin, metabolism, and body temperature &ndash; each of which is in charge of regulating the natural cycle of your bodily functions and chemical changes.&nbsp;

&nbsp;

Circadian rhythm is the most well-known and the most significant factor in maintaining a cycle that encourages sound sleep and function. It tracks alterations in the environment (such as variations in light and darkness) and then informs and instructs the brain when it&rsquo;s time to sleep or wake up. 
&nbsp;

The need for sleep is a universal biological necessity that has been maintained across species despite evolution. Factors like duration, continuity, and intensity (depth) of sleep with no disruption to the circadian rhythm need to be ensured to be able to enjoy high levels of attention and cognitive functioning throughout the wake period.&nbsp; 
&nbsp;

So, in case of any circadian rhythm disturbances, be ready to experience changes to vital bodily processes, like:

<ul>
	<li>Hormone regulation</li>
	<li>Body temperature</li>
	<li>Pattern of eating and metabolism 
	&nbsp;</li>
</ul>

For instance, the hormone responsible for sleep, melatonin, is produced under the direction of the suprachiasmatic nucleus (SCN). The optic nerves transmit the data from your eyes to your brain, providing crucial information like the intensity of incoming light to it. When there is less light, the SCN will instruct the brain to produce more melatonin, which will make you sleepy.

&nbsp;

But a possibility is that you&rsquo;re simply cooped up in a relatively dark room while it&rsquo;s day outside. Or it could be that it&rsquo;s night outside, but you&rsquo;re up studying for an exam. Your body gathers data from the immediate surrounding, and interprets it accordingly. These incidents mess up your circadian rhythm.&nbsp;

&nbsp;

Short-term, this disruption can cause lethargy, attention loss, and overall poor health; long-term, there can be a lot of pathological issues, like diabetes, obesity, cancer progression,<a href="https://merisehat.pk/disease/anxiety"> anxiety</a>, and psychiatric disorders<a href="#accordion">[2]</a>. 
&nbsp;

Do you know there&rsquo;s a whole list of circadian rhythm sleep-wake disorders that experts have classified according to their symptoms and causes? Some of them are<a href="#accordion">[6]</a>: 
&nbsp;

<ul>
	<li>Jet Lag Disorder</li>
</ul>

This happens when a person travels through several time zones quickly. You must have experienced it &ndash; or heard about it from a friend or a relative &ndash;after an international flight. And these jet lag sleep issues and exhaustion continue until the circadian rhythm adjusts to the day-night cycle of the new location. 
&nbsp;

<ul>
	<li>Shift Work Disorder</li>
</ul>

A person&#39;s circadian rhythm can be severely disturbed by work requirements. For instance, sometimes your job requires you to work in shifts. As a result of this rotation, you sleep during the day and work during the night. Journalists often operate in this manner. Freelance workers, serving a client from the other end of the world suffer from this disorder too. Yes, work&rsquo;s important, money&rsquo;s important; but, at the end of the day you struggle just to stay awake &ndash; or fall asleep &ndash; because there&rsquo;s a conflict within your body and you&rsquo;re acutely aware of it. 
&nbsp;

<ul>
	<li>Advanced Sleep Phase Disorder</li>
</ul>

You should go visit a doctor if you tend to fall asleep quickly in the evening and wake up relatively early as well. Yes, that&rsquo;s a sleep disorder, too. If you have an advanced sleep phase disorder, you won&rsquo;t be able to stay up longer at night or sleep later in the morning, even if you want to. But it&rsquo;s not a frequent ordeal given that it affects only 1% of the population in the world, particularly the older people. This one&rsquo;s a hereditary issue, though; a change of environment may reduce the impact but it won&rsquo;t end it effectively. 
&nbsp;

<ul>
	<li>Delayed Sleep Phase Disorder</li>
</ul>

This kind of disruption of the circadian rhythm is the opposite of advanced sleep phase disorder. It is commonly seen among the &rsquo;night owls,&rsquo; people who stay up late and sleep in late. This affects a handful of the population, too &ndash; only 1-2 people out of every 1,000 people. However, zooming in on the problem, you&rsquo;ll find out that nearly 16% of the affected population are teenagers.&nbsp;

&nbsp;

So, you might be up all night, staying in and trying to finish the rerun of FRIENDS or going out with friends and partying hard; don&rsquo;t force yourself to do something, anything, to stay awake when your body would rather be at rest. However, consult a doctor when you feel things are spiralling out of your control and you can&rsquo;t help but stay awake at night for no reason. It is also important to consult a doctor since some studies suggest this disorder stems from some underlying health issues and it may be hereditary, too. So, don&rsquo;t ignore it.&nbsp; 
&nbsp;

<ul>
	<li>Non-24-Hour Sleep Wake Disorder&nbsp;</li>
</ul>

You may be able to observe this one in a loved one who is blind. Since they won&rsquo;t be able to get light-based cues for their circadian rhythm, they&rsquo;ll be especially vulnerable to develop this kind of disorder. The interesting thing to note here is that, even though their sleeping schedule keeps changing, moving backwards by a couple of minutes or by hours, their body is able to maintain its 24-hour cycle.&nbsp; 
&nbsp;

<ul>
	<li>Irregular Sleep-Wake Rhythm Disorder</li>
</ul>

Given its symptoms, it&rsquo;s kind of hard to believe that this disorder is rare. Irregular sleep-wake rhythm disorder is a term for those people who take numerous naps or experience brief intervals of sleep spread throughout a 24-hour day. Sounds familiar? Don&rsquo;t just self-diagnose, yet. This disorder is related to brain disorders, such as dementia or traumatic brain injury, which impair proper functioning of the circadian rhythm in the hypothalamus<a href="#accordion">[3]</a>. Yes, you see it now, don&rsquo;t you? If in doubt still, it&rsquo;s better to consult a doctor.&nbsp;&nbsp; 
&nbsp;

As the list shows, there can be a number of reasons why you have circadian rhythm problems:

&nbsp;

<ul>
	<li>It can be due to personal/professional reasons, like working or traveling.&nbsp;</li>
	<li>It can be due to an underlying problem that impairs your capacity to recognize or process environmental cues that control your body&#39;s internal clock.&nbsp;</li>
	<li>It can be a genetic factor.&nbsp;</li>
	<li>It has no known cause. 
	&nbsp;</li>
</ul>

If you made it this far, good for you! What you need to understand now is that irregular circadian rhythm is primarily managed through behavioral therapies. At this stage, it&rsquo;s important to differentiate between acute and chronic circadian rhythm disorders, and primary and secondary illnesses since this will have an impact on the development of evaluation and treatment strategies. 
&nbsp;

The following are some examples of circadian rhythm disruption treatment<a href="#accordion">[7]</a>:

<ul>
	<li>Behavioral therapy</li>
	<li>Chronotherapy</li>
	<li>Bright light therapy</li>
	<li>Lifestyle changes</li>
	<li>Enhancing environmental cues</li>
	<li>Mixed modalities</li>
	<li>Pharmacotherapy</li>
	<li>Nonbenzodiazepine hypnotics (e.g., eszopiclone, zolpidem, zaleplon)</li>
	<li>Orexin receptor antagonists (e.g., suvorexant)</li>
	<li>Benzodiazepines (e.g., triazolam, flurazepam, estazolam, temazepam, quazepam</li>
	<li>Melatonin receptor agonists (e.g., ramelteon, tasimelteon, melatonin) 
	&nbsp;</li>
</ul>

Without awareness and conscious efforts to change your behavior, your lifestyle can continue to impede a restful night's sleep. Don’t worry; it’s totally feasible and requires only minor tweaks to your sleeping environment.&nbsp; <ul><li>Screens</li></ul>Screen exposure is one of the toughest habits to break. The strong white-blue light from your devices inhibits melatonin production, while increasing the production of cortisol. Make sure to restrict your screen time after sunset. <ul><li>Electromagnetic Fields (EMF)</li></ul>Wi-Fi routers, smartphones, the interior base of a wireless phone set, outside cellular antennas, and maybe nearby smart meters all emit EMFs. Avoid sleeping with your phone in or adjacent to your bed; if necessary, try using airplane mode on the phone at night. Also, relocate the wireless phone base and Wi-Fi router to a different room. <ul><li>Light</li></ul>Your body and mind require darkness when you sleep, so try to block as much light from the room as possible. You can try blackout curtains if the streetlights outside your window are too bright.&nbsp; <ul><li>Other Considerations&nbsp;</li></ul>There are two more lifestyle modifications that can enhance your sleep. One, you should avoid drinking liquids (e.g. coffee, water) before bed. And, two, just like we do it for the newborns, create a regular sleep routine for yourself to ensure you get a good night’s rest.&nbsp;

Conclusion

Your body naturally maintains a 24-hour body clock (also known as circadian rhythm) that influences (and, consequently, is influenced by) your sleep&ndash;wake cycle. You can preserve this vital function through a healthy and active lifestyle, which includes adequate rest.

&nbsp;

If you persistently have trouble falling asleep or feel excessively tired during the day, you should consult a doctor to learn how to reestablish your circadian rhythm and receive the rest you need. 
&nbsp;

Key Points

<ul><li>Your circadian rhythm is a combination of physiological changes that occur over 24 hours.</li><li>The degree of light and darkness in your surroundings will impact this cycle, affecting your health, sleep and eating patterns, and brain function.</li><li>There are numerous aspects of contemporary life that hamper a healthy circadian rhythm, but you can take concrete steps to maintain your own sleep-wake cycle.</li></ul>

[1] Roenneberg T, Merrow M. The circadian clock and human health. Curr Biol. 2016;26(10):R432--R443.

[2] Serin Y, Tek NA. Effect of circadian rhythm on metabolic processes and the regulation of energy balance. Ann Nutr Metab. 2019;74(4):322–30.

[3] Barion A, Zee PC. A clinical approach to circadian rhythm sleep disorders. Sleep Med. 2007 Sep;8(6):566–77.

[4] Ohayon M, Wickwire EM, Hirshkowitz M, Albert SM, Avidan A, Daly FJ, et al. National Sleep Foundation’s sleep quality recommendations: first report. Sleep Heal. 2017;3(1):6–19.

[5] Mary E Cataletto MD. Sleeplessness and circadian rhythm disorder. Practice Essentials, Background, Etiology.

[6] Circadian rhythm. Sleep Foundation.

[7] Melinosky C. Circadian rhythm disorder (exams and tests). WebMD.

Neelam Asad

How To Make Mondays Less Dreadful: Understanding The Impact Of Sleep And Circadian Rhythms

Mondays have long been known as the most dreaded day of the week, with most people struggling to transition from the freedom of the weekend to the restrictions imposed on us by our weekday responsibilities. However, recent research has shown that there is more to this reputation than just a cultural myth. Mondays have been associated with a higher likelihood of heart attacks, strokes, emotional stress, lower productivity, and even higher suicide rates. 
&nbsp;

Mondays

<ul>
	<li>Sleep and Circadian Rhythms: The foremost reason for the toll that Mondays take on us is sleep. On weekends, we tend to wake up later and stay up later, disrupting our body&#39;s circadian rhythms. Our bodies are governed by a 24-hour circadian rhythm that regulates hormones and neuromodulators that impact our sleep patterns, mood, and energy levels. When we sleep and wake up determines when certain chemicals are released, and when these chemicals are released impacts our level of fatigue and wakefulness. Hormones like cortisol and melatonin are particularly affected, leading to hormonal dysregulation that can impact organ functioning, cognitive impairment, and lowered productivity. 
	&nbsp;</li>
	<li>Psychological Factors: In addition to the biological factors, the psychological toll that Mondays take on some of us can compound the problem. Weekends bring a sense of freedom, but on Mondays, our time is once again tied up in service of an outside entity. This can leave us feeling a loss of freedom and autonomy, particularly if we don&#39;t enjoy our jobs. Our culture of demonizing Mondays only adds to this, and excessive indulging in alcohol and food over the weekend can make Mondays seem insurmountable. 
	&nbsp;</li>
	<li>Mitigating the Impact: Fortunately, there are steps we can take to mitigate the negative impact of Mondays. The most essential step is to try and stay on a sleep schedule that is not too much of a departure from the working week. On Sunday evening, take some time to prepare for the next day. List down the tasks you have lined up, do a short meditation to visualise what your Monday morning will be like, and perhaps engage in a self-care routine before going to bed, such as doing a yoga flow, lighting some candles, or taking a long bath. 
	&nbsp;</li>
</ul>

Although Mondays will never be completely stress-free, by understanding the impact of sleep and circadian rhythms, we can take steps to mitigate the negative effects. By incorporating preparation into our weekend routines, we can start the work week feeling a little more in control and a little less stressed.

Ayesha Binte Rashid

There could be a plethora of reasons why we would want to reset our circadian rhythm. It could be that we&rsquo;re feeling less productive during the workweek. Being late to work and being unable to meet deadlines does us no good. But it&rsquo;s not just the work; this misalignment creeps in and affects our daily lives. We know who or, rather, what to blame; it&rsquo;s the irregular sleep schedule we&rsquo;ll claim. But the issue is that why, as young, apparently responsible adults, can&rsquo;t we sleep and wake up on time? What&rsquo;s amiss?&nbsp;

&nbsp;

Is it due to jet lag? Is it because we stayed up late on that one weekend &ndash; only to regret it throughout the week? A never-ending cycle of why we&rsquo;re failing to keep up with our commitments &ndash; both personal and professional &ndash; that fuels our stress further until we&rsquo;re back to square one: can&rsquo;t sleep, therefore can&rsquo;t wake up.&nbsp; 
&nbsp;

Ugh! It&rsquo;s exhausting! No one&rsquo;s happy, ourselves included, and on top of it even our health is suffering.

&nbsp;

The positive news is that a circadian reset is possible. Yes, just like we reset the morning alarms on the phone, we can control the time that our body sleeps and wakes up. Given our current scenario, this means we have this power to literally change the time we sleep and wake.

&nbsp;

Feeling doubtful? Let&rsquo;s read on to find more about circadian rhythm, what it is and how to achieve it.

<div>&nbsp;</div>

Understanding the Basics of Circadian Rhythms

According to the National Institute of General Medical Sciences (NIGMS), circadian rhythms are the body&#39;s natural internal clock that follows a 24-hour cycle<a href="#accordion">[7]</a>.

&nbsp;

All the physical, mental, and behavioral changes that our body undergoes during this period are influenced by the amount of light and darkness in our surroundings. This includes the infamous sleep-wake pattern; even our bodies are attuned to sleep at night and be awake during the day.

&nbsp;

Besides light, factors like age, physical activity, social behaviors, and hormones (e.g., melatonin) influence our body&rsquo;s internal clock as well. Almost every organ and tissue in our bodies have these biological clocks or proteins to regulate the circadian rhythms.

&nbsp;

According to the NIGMS, animals, plants, and microorganisms follow the cycle of circadian rhythms as well. It&rsquo;s what instructs nocturnal animals to not go out during the day. It&rsquo;s also why flowers open and close at the right time.&nbsp; 
&nbsp;

On average, a person needs 6-9 hours of sleep in a day. Due to these individual differences in our circadian rhythms, it&rsquo;s possible that some people&rsquo;s internal biological clocks run shorter than 24 hours as compared to others. 
&nbsp;

<h5>Male vs Female</h5>

A number of studies on sleep patterns and wakefulness were examined by researchers who found that males are more likely to be active at night, while females are more likely to wake up early and be more active throughout the day. In addition, females were more immune to interruptions in their regular circadian rhythm than males, making them less susceptible to disruptions when they were sleeping. In contrast, men tend to nap more frequently in the afternoon<a href="#accordion">[9]</a>. 
&nbsp;

<h5>Infants vs Adults&nbsp;</h5>

The circadian rhythm&#39;s components develop after delivery in a newborn baby<a href="#accordion">[3]</a>. Cortisol rhythms start to emerge at 8 weeks of age, whereas melatonin and sleep efficiency rhythms emerge at around 9 weeks followed by body temperature rhythms, and circadian gene rhythms emerge at around 11 weeks<a href="#accordion">[4]</a>.&nbsp;

&nbsp;

The newborn has a shaky sleep-wake pattern, closely linked to the mother and develops further as the baby grows. Timing, length, and quality of sleep are just a few of the changes linked to aging.&nbsp;

&nbsp;

In adults, the human circadian period ranges between 23.5 and 24.5 hours. It is synchronized to the 24-hour day by signals received from the surroundings<a href="#accordion">[6]</a>. Adults aged 60 and above experience a shift known as a phase advance, which causes them to function more in the morning and to nod off earlier in the evening<a href="#accordion">[6]</a>. 
&nbsp;

There is a fairly symbiotic relationship between exercise and sleep<a href="#accordion">[1]</a>. A good sleep-wake cycle enables us to have more endurance and strength while exercising and, vice versa, i.e. appropriate exercise increases our sleep quality.&nbsp;

&nbsp;

Working out too close to bedtime, though, is not helpful; it leaves us too alert and stimulated to sleep. Exercise is definitely useful if we are not getting enough nighttime sleep and would like to realign our circadian cycle. However, timing is crucial; it&rsquo;s better to avoid exercising 1-2 hours before we intend to go to bed<a href="#accordion">[8]</a>. 
&nbsp;

<h5>How does Diet help Maintain Good Circadian Rhythms?</h5>

A common mistake is to confuse circadian rhythm disorder with night eating disorder (NED). Remember, these are two separate conditions. NED is primarily an eating disorder that causes people to wake up during the night to eat; they are unable to fall asleep again if they don&rsquo;t eat. Circadian rhythm is when our body&rsquo;s natural clock is messed up and you feel tired, hungry, and alert at odd hours throughout the day; it may cause NED, but it&rsquo;s not the same since it affects all systems of our body. 
&nbsp;

Dietary recommendations to maintain good circadian rhythm comprise of the following:

<ul>
	<li>Minimize large meals</li>
	<li>Avoid consuming excessive fluids before bed</li>
	<li>Focus on healthy weight loss 
	&nbsp;</li>
</ul>

<h5>Caffeine</h5>

This warrants a separate section because of its excessive consumption. For shift workers, jet-lagged travelers, and other people who feel sleepy, caffeine works as a powerful albeit brief stimulant. It makes them feel alert, energetic, and even confident. However, caffeine intake for a healthy adult, has a half-life of 5 hours, which means our bodies typically take 5 hours to excrete half the quantity consumed<a href="#accordion">[2]</a>. Therefore, they need to start the day with a modest amount of coffee and stop at least 5-7 hours before night to achieve the best outcomes.&nbsp; 
&nbsp;

A social or environmental cue known as a &quot;zeitgeber&quot; (German for &quot;time giver&quot;) affects and synchronizes our biological cycles. It acts as a trigger to start or stop the biological clock.

&nbsp;

Natural sunshine is the most significant zeitgeber, but meal times, body temperature, and exercise are also significant zeitgebers. Alarm clocks and schedules for school/work that are intended to keep us on a fixed schedule could also be regarded as zeitgebers. 
&nbsp;

<h5>Seasons</h5>

The biggest seasonal effects on wake time and sleep length are typically observed during the spring season. We tend to wake up earlier during spring as compared to the winter season. A small reduction in sleep time occurs as days get longer, i.e., between the winter and summer solstice<a href="#accordion">[10]</a>. 
&nbsp;

Evidence reveals that circadian rhythms and sleep quality have an impact on a number of hormones and metabolic processes. Sleep and circadian rhythmicity are found to be strongly linked to growth hormone, leptin, cortisol, melatonin, and ghrelin among other hormones<a href="#accordion">[11]</a>. 
&nbsp;

Getting up at the same time each day is important in this regard. When we maintain a consistent sleep schedule, we&rsquo;re able to reset our circadian clock. Our bodies learn to adapt to the new rhythm when we start going to bed and getting up at the approximately same time on a regular basis.&nbsp; 
&nbsp;

Pro Tip:&nbsp;Schedule an alarm so you can wake up at the designated time even if you can&#39;t fall asleep at the time you&#39;d like to. This will help you maintain your rhythm. 
&nbsp;

Bright artificial light exposure has a significant control over our circadian rhythms. For shift workers or those whose work schedules involve late nights and/or early mornings, timed exposure is very effective<a href="#accordion">[13]</a>. There are various light treatment tools out there, such as light boxes, desk lamps, and dawn simulators<a href="#accordion">[12]</a>.&nbsp; 
&nbsp;

Note:&nbsp;Always consult a qualified sleep medicine physician about the amount of light therapy and the periods of the day that are most appropriate to your unique circadian rhythm before you invest in the devices. 
&nbsp;

There are a few tiny nuclei right at the center of our brains known as suprachiasmatic nuclei (SCN). They act as command posts for all the other brain regions and together, they regulate various bodily processes, including circadian rhythms. The duration of a full cycle is close to 24 hours for the majority of people.

&nbsp;

Ideally, the older we get, the more likely we&rsquo;re to go to bed around 7 in the evening and wake up around 3-4 in the morning. However, a lot of us choose to delay going to bed for hours rather than giving in to our innate desire to sleep. So, when their body clock takes over and sends a wake-up call to the body at 3 a.m., it disrupts their sleep schedule.

&nbsp;

Thus, we&rsquo;ll see older people around us complaining of poor sleep quality, i.e., they have more light sleep (5 hours or less) and very little deep or REM sleep. Moreover, they tend to wake up 3-4 times during the night, which gives them the perception that they have been awake for the entirety of the night. 
&nbsp;

The following are some methods to stop disorders of the circadian rhythm:

<ul>
	<li>Implement sound sleeping practices</li>
	<li>Control sleeping environment and limit exposure to light and dark</li>
	<li>Adjust schedules to the local time before traveling in case of jet lag issues</li>
	<li>Rotate the timetable counterclockwise for shift employees as it is more tolerable 
	&nbsp;</li>
</ul>

Our circadian rhythm is significantly influenced by light and darkness. However, there are other influences at work as well, some of which are internal while some are external.&nbsp;

&nbsp;

Unbalanced circadian rhythm-related sleep issues are more frequent than we can imagine. It&rsquo;s important to consult a medicine practitioner who can guide us regarding the lifestyle changes we need to make for a holistic approach to better sleep. 
&nbsp;

<ul>
	<li>The circadian clock, a tiny area of the brain, synchronizes the body with day and night.</li>
	<li>The circadian clock controls bodily activities, like heart rate, blood pressure, temperature, digestion, and brain activity.</li>
	<li>Shift workers are more likely to have health issues, such as digestive upsets, <a href="https://merisehat.pk/disease/obesity">obesity</a>, heart disease, and accidents, due to excessive daytime sleepiness.</li>
	<li>Maintaining a good rhythm is very important for health and social life.</li>
</ul>

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[9] Miller K. Males and females have different circadian rhythms, study finds. Verywell Health.

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