Lack of Sleep

Every human needs sleep to live. That is true with many other functions like drinking and eating. And just like drinking and eating, there is a certain limit we must meet in order to be considered healthy. For most people, it is recommended that they get around eight hours of sleep. Unfortunately, most people don’t meet that amount of time. Not only does this disrupt a basic function, but this also affects many other bodily activities or even parts of your brain.

Lack of sleep is known for having many different adverse side effects. These side effects include: daytime sleepiness, fatigue, irritability, forgetfulness, lack of motivation, obesity, weakened immune system, and increased risk for heart disease (Davis). All of these side effects can be easily explained when looking at how sleep can lower these symptoms. Sleep aids in compiling and organizing experiences from the day, this explains why a lack of sleep can lead to forgetfulness. Sleep allows our body to produce for cytokines, which fights infection, meaning a lack of sleep would reduce the production of cytokines (Davis). Sleep also allows our heart vessels to heal which explains why a lack of sleep would increase our risk for cardiovascular disease.

Speaking of cardiovascular disease, sleep deprivation is linked to many types of heart disease including coronary and ischemic heart disease. “According to a 2017 study, published in the European Heart Journal, of nearly 13,000 adults, people who experience poor sleep from issues like lack of sleep, dependence on sleeping pills, or sleep-disordered breathing have a 71% higher risk of ischemic heart disease and a 45% higher risk of stroke” (Tuck). Another study in the European Heart Journal found that too short of sleep or too much sleep can increase the buildup of calcium deposits which is a risk factor in coronary heart disease (Tuck). The study compiled information for others and found that “475,000 individuals who slept fewer than 6 hours had nearly a 50% higher risk of dying from coronary heart disease seven to 25 years later, and a 15% increased risk of stroke” (Tuck). They also found that people who slept longer than 9 hours had an even higher risk of stroke at 65%, and a risk of coronary heart disease at 38%. These studies show the importance of the recommended daily amount of sleep, which is around 8 hours. Although other factors can be attributed to these risks like obesity or smoking, poor sleep can account for most of these risks independent from other factors (Tuck).

One of the most famous cases of the negative effects of sleep deprivation the both the mind and personality was when Peter Tripp hosted his radio show for more than 200 hours in 1959. His colleagues and listeners noticed that he became irritable and less like himself. Studies have been conducted focusing on irritability and lack of sleep. In one study, when sleep deprived participants were shown emotionally negative images, activity levels in the amygdala were as much as 60% higher than levels in those who were rested (Tamminen). The study found that sleep deprivation had disrupted the connection between the amygdala and the medial prefrontal cortex (Tamminen). This means that sleep deprivation can disconnect the amygdala from its own source of moderation, explaining why some become irritable after not getting enough sleep.

A notable long-term effect of chronic sleep disturbances is memory loss and brain damage. Research has pointed to the possibility of sleep loss contributing to cognitive impairment and memory loss in older people (University Health News). A possible link can be seen when studying patients with memory disorders. Patients with dementia or Alzheimer’s commonly have sleep disturbances (U.H.N). A study published in Neurology showed that people who spent less time in slow wave sleep had an increase in brain atrophy (U.H.N). Sleep apnea, a disorder which interrupts sleep due to the inability to breath, results in high levels of brain damage due to the lack of sufficient oxygen reaching the brain.

As mentioned previously, sleep apnea is a disorder which interrupts sleep due to a lack of sufficient oxygen intake. Not only can it lead to brain damage, but it can also cause a multitude of other effects. Some of these effects include: depression, acid reflux,low blood oxygen levels, high blood sugar levels, and higher risk of stroke and fatty liver disease (Watson). People with sleep apnea are more likely to develop insulin resistance, increasing their risk for Type 2 Diabetes (Watson). If you have sleep apnea, you are more likely to have an abnormal heart rhythm with the heart palpitations also disrupting your sleep (Watson, Tuck). With constant deprivation of oxygen while sleeping, people with sleep apnea can worsen symptoms of asthma chronic obstructive pulmonary disease, also known as emphysema and chronic bronchitis (Watson). Luckily, there are ways to treat sleep apnea like continuous positive airway pressure machines, or CPAP, which aid in providing patients with sufficient levels of oxygen while they sleep.

When discussing sleep, or in this case a lack of sleep, it is almost a necessity to mention melatonin. Melatonin is a hormone which is enterns your blood and makes you feel tired and less alert. Melatonin is released in response to natural or artificial light. Exposure to light stimulates a nerve pathway from the retina to the hypothalamus. In the hypothalamus, the suprachiasmatic nucleus responds to the light stimulation by sending signals to other parts of the brain directing the control of hormone production. During the day, when there is an abundance of light, the pineal gland remains inactive, but at night, the SCN activates it and produces melatonin. When on the computer, your phone, or watching tv at night, this form of light inhibits the production of melatonin which leads to a lack of sleepiness and in turn can lead to sleep deprivation (National Sleep Foundation). Unfortunately, melatonin supplements have been on the rise and many doctors are prescribing them to patients who are sleep deprived. Like other medications, melatonin does not work for everyone and is not a miracle drug. Side effects include dizziness, headaches, nausea, and small changes in blood pressure and the use of melatonin can worsen existing sleep issues (Lester). A good way to promote a healthy production of melatonin is to reduce the amount of exposure to artificial light, mostly blue light, before you go to bed. Unless you are in a dimly lit room, your brain will still think it is daytime, thus confusing both your bodily functions and your circadian rhythm.

Just like melatonin, our body produces other hormones and neurotransmitters that promote either wakefulness or inhibit it. The hypothalamus, for example, contains numerous amounts of neurons that release both neurotransmitters that promote wakefulness or promote sleepiness. Some of these neurons produce GABA and galanin which inhibit dopamine, histamine, norepinephrine, and serotonin, all of which induce wakefulness (Wannissorn). A small cluster of the orexin neurons in the hypothalamus control other neurons that promote wakefulness, including neurons that secrete cholines, dopamine, noradrenaline, and serotonin in the cerebral cortex (Wannissorn). Altered dopamine (crucial for arousal and motor function and released from neurons in the substantia nigra, ventral tegmental area and periaqueductal grey) levels can lead to neurological disorders like Parkinson’s, schizophrenia, and ADHD (Wannissorn and Guzman). People with these disorders often show disturbances of sleep, excessive daytime sleepiness, and REM sleep disorders (Wannissorn). Although serotonin can be released to promote alertness and arousal, it can also be produced to improve sleep quality. 5-HTP (precursor to melatonin and serotonin) does just that. Other parts of the brain, like the pons, release norepinephrine from the locus coeruleus. Norepinephrine acts as an arousal neurotransmitter which increases wakefulness much like dopamine and histamine. The main inhibitory neurotransmitter, GABA, is produced by more than 20% of the brain’s neurons (Wannissorn). This neurotransmitter promotes sleep by inhibiting brain regions involved in wakefulness and inhibiting parts of our nervous system (Wannissorn and Guzman). All of these neurotransmitters work together to ensure that we fall in line with one of our most important daily bodily function.

In conclusion, even though many people believe they are able to function with only a few hours a sleep every day, they do not understand the amount of stress and hardship they put they body under when they are sleep deprived. Being able to function day to day is not the same as being a healthy person. Maybe as a society, we should focus on how we view life, not as a struggle to fight time, but to embrace it and accept that we do need time to rest and heal.

Work Cited

Davis, Kathleen (2018). “What's to know about sleep deprivation?” Medical New Today.

Retrieved from https://www.medicalnewstoday.com/articles/307334.php

Guzman, Flavio (2018). “Psychopharmacology of Sleep and Wakefulness:

Understanding Neurotransmitters and Pathways in Clinical Practice” Pharmacology Institute. Retrieved from https://psychopharmacologyinstitute.com/sleep-insomnia/psychopharmacology-sleep-wakefulness-understanding-neurotransmitters-pathways-clinical-practice/#Dopamine

“Heart disease and sleep” (2018). Tuck. Retrieved from https://www.tuck.com/heart-disease-and-sleep/

“Lack of Sleep Side Effects: The Link Between Sleep Deprivation, Brain Damage, and Memory.” (2018) University Health News. Retrieved from https://universityhealthnews.com/daily/sleep/lack-of-sleep-side-effects-the-link-between-sleep-deprivation-brain-damage-and-memory/

Lester, Tiffany (2017). “This is Why Melatonin Doesn’t Help Everyone Sleep.” Parsley Health Retrieved from https://www.parsleyhealth.com/blog/melatonin-doesnt-help-everyone-sleep/

“Melatonin and Sleep” National Sleep Foundation. Retrieved from https://www.sleepfoundation.org/sleep-topics/melatonin-and-sleep

Tamminen, Jakke (2016). “How a lack of sleep affects your brain – and personality”

The Conversation. Retrieved from http://theconversation.com/how-a-lack-of-sleep-affects-your-brain-and-personality-66604

Wannissorn, Nattha (2018). “How Brain Health & Neurotransmitters Affect Sleep” SelfHacked. Retrieved from https://www.selfhacked.com/blog/sleep-neurophysiology/

Watson, Stephanie (2017). “The Effects of Sleep Apnea on the Body.” Healthline. Retrieved from https://www.healthline.com/health/sleep-apnea/effects-on-body#1   

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