It’s the occurrence that everyone looks forward to after a long day, whether it pertains to coming back home from school or a tedious day at the workplace: sleep. Some may view it merely as a time to rest and rejuvenate, although this is only partially true. In fact, there’s a more psychological reason as to why it’s such an important part of one’s day that goes beyond a mere rest period. Not only can it make one feel more energized, it helps both your mind and your body in various different ways

The Importance of Sleep

It is estimated that roughly a third of our lifespan is spent asleep, which is a very significant amount of time. This means that a person spends at least 26 years of their life sleeping (1). You have likely heard people recommend that you sleep earlier for a variety of reasons, ranging from reasons like not feeling as tired when you wake up to the betterment of your mental or physical wellbeing. Indeed, sleep has a plethora of benefits attached to it. Quality sleep is linked to aspects such as improved memory, a better mood and emotional regulation, a stronger immune system, a lower risk of chronic health conditions such as heart disease and diabetes, and more (2).

Psychology of Sleep: Stages

There are 2 stages of sleep, which are NREM (non-rapid eye movement) and REM (rapid eye movement) respectively. Within NREM, there are 3 stages of sleep: N1, N2, and N3.

The first stage, N1, is the light sleep stage. It generally lasts around 1-5 minutes and takes up only 5% of one’s total sleep. In stage 2 or N2, the heart rate and body temperature begins to drop. This phase takes up 45% of your sleep. The presence of sleep spindles is what characterizes this phase (3). Sleep spindles are short, strong bursts of neuronal firing that are believed to play a role in brain plasticity (process of learning and encoding new memories) (4). Stage 3, N3, is the deepest stage. It’s known as the deepest non-REM sleep stage and takes up 25% of your sleeping period. It’s also the hardest to wake up from, as loud noises greater than 100 decibels won’t even be enough to rouse someone from their slumber. If someone were to wake up while in this stage however, they’d experience the phenomenon of mental fogginess which is also known as sleep inertia. The body also repairs itself, building bone and muscle as well as strengthening the immune system within this stage (3).

REM sleep is not necessarily a sleep stage, but is instead associated with the capacity to dream. The only parts of the body that are active here are the eyes and the muscles associated with breathing in your diaphragm. This period of sleep takes up roughly 25% of your sleep cycle (3).

How Much Sleep is Considered Enough?

This question is trickier to answer, as it differs person to person. Generally, the amount of sleep needed goes down as you age. Newborns, for instance, need about 14-17 hours of sleep whilst an adult 65 years or older only needs 7-8 hours. Toddlers need 11-14 hours, but teens only need 8-10 (5). Of course, if you’re already sleep deprived, you may have to make up for it by sleeping more than you otherwise would depending on which age group you fall within.

Sleep Disorders and Other Issues

Despite sleep being so important, it’s estimated that 1 in 3 U.S. adults do not get enough sleep everyday. Meanwhile, an estimate of roughly 50 to 70 million U.S. adults have either chronic or ongoing sleep disorders (6). Poor sleep is associated with a weaker immune system and thus physical conditions like the aforementioned issues of heart disease and diabetes. However, lack of sleep could be due to a plethora of reasons: general stress, high demands for work or school, or an addiction to the internet or social media. It could also be related to specific sleep disorders.

Insomnia is a common one that may come to mind. This condition may affect 10-30% of the global population (7) and torments quite a lot of people on the daily. Symptoms can be episodic (lasting 1-3 months), persistent (lasting more than 3 months), or recurrent (2 or more episodes occurring within a year). It generally includes problems falling asleep or staying asleep (8).

Obstructive sleep apnea or OSA is another common sleep disorder, which is thought to affect roughly 2-9% of the adult population (9). This is the disorder in which breathing may repeatedly stop and start while asleep because of an airway that’s either narrowed or blocked (10). It is especially prevalent in males (11), and even more so as age increases for both genders. This is why you might have a father that snores very loudly at night.

Those are only 2 of the more common sleep disorders that this article will discuss. However, they’re not the only ones. There are numerous other sleep disorders, including restless leg syndrome or RLS, narcolepsy, and disorders that affect the circadian rhythm such as jet lag and shift work disorder. It’s worth looking into them, especially if you know a loved one that may have one of the aforementioned conditions.

Conclusion

Though brushed off as rest that feels nice to have, sleep is so much more important than one may give it credit for. It’s linked to a variety of health benefits and is important to the body in ways you wouldn’t even be able to comprehend. Sleep in itself is still being understood, such as the importance of those sleep spindles that were discussed earlier. Both too much sleep and too little sleep can be detrimental to one’s well-being in various ways. as it is deeply intertwined with various functions of the body. Sleep should make you feel rejuvenated, so make sure you get enough of it. Just make sure the deeper implications of sleep don’t keep you up for too long at night.

Sources:

Our Life in Numbers: How Long We Sleep, Work & More | Dreams (1)

Benefits of Sleep: Improved Energy, Mood, and Brain Health (2)

Physiology, Sleep Stages - StatPearls - NCBI Bookshelf (3)

What are Sleep Spindles? (4)

About Sleep (5)

What Are Sleep Deprivation and Deficiency? | NHLBI, NIH (6)

Prevalence of chronic insomnia in adult patients and its correlation with medical comorbidities - PMC (7)

Psychiatry.org - What are Sleep Disorders? (8)

Sleep by the Numbers - National Sleep Foundation (9)

Obstructive sleep apnea - adults (10)

Obstructive sleep apnea detection and prevalence in men and women using a continuous large U.S. sample by home under-mattress devices - PubMed (11)