5 Shocking Ways Sleep Deprivation or Insomnia Affects Your Body

by | Last updated Feb 24, 2022

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We’ve all experienced a sleepless night or two. Yet the lack of sleep side effects you likely didn’t realize are connected, may convince you it’s time to take your sleep seriously.

Recently, a spike in reports of disturbed sleep caused by stress and anxiety related to COVID-19 are coming in. In fact, it’s so commonplace a new term coined “Coronosomnia” has emerged to explain the sleep problems related to the pandemic.

Although getting a good night’s sleep is fleeting for some, and is considered relatively harmless by many, it can have a profound negative affect on your health.

Whether your sleep deprivation stems from insomnia triggered by the coronavirus or other causes, it’s best to address the underlying causes to ensure you’re getting the recommended 7-9 hours of sleep at night, and help resolve your insomnia before it becomes chronic and has lasting effects on your health.

Listed below are five shocking ways sleep deprivation and insomnia affects your body.

What is Insomnia?

Before we share how insomnia affects your body, it’s important to understand what insomnia is and why you’re experiencing it.

Insomnia is the inability to sleep, whether it’s difficulty falling asleep or staying asleep at night. It leads to sleep deprivation, and results in non-restorative sleep. If you’ve ever awakened feeling unrefreshed in the morning after tossing and turning or laying awake in bed unable to sleep then you’ve likely experienced acute insomnia.

Acute insomnia is the most common form and typically occurs when a stressful event occurs. In fact, according to a recent study from the University of Pennsylvania School of Medicine every year 25 percent of Americans experience acute insomnia. Other studies report numbers exceeding one out of four Americans

If you have acute insomnia you may struggle to fall asleep or stay asleep for a few nights each week up to three months. For most people it won’t extend beyond that, but for six percent of Americans it turns into chronic insomnia.

Acute Insomnia vs Chronic Insomnia

Acute insomnia is shorter in duration and is typically triggered by an isolated stressful situation or traumatic event in your life. It can also be related to external elements such a heatwave or sensitivity to noise or light. Medications or sickness can also be a trigger.

Chronic insomnia occurs three or more nights a week and lasts at least three months. It may result from poor sleep routine or eating habits, medical conditions, or overall stress, mental disorders or substance abuse.

Lack of sleep side effects affect your body even after one night of fragmented, disrupted or shorter duration of sleep. So it’s important to address your sleep deprivation or acute insomnia early on, so it can help prevent acute insomnia from transitioning into chronic insomnia.

1. Insomnia Weakens the Immune System

Can a lack of sleep make you sick?

In a word, yes. Especially right now during a pandemic, this lack of sleep side effect shouldn’t be ignored! Quality sleep is essential for T Cells to destroy cells carrying viruses. Less sleep reduces T Cell response in the body.

Sleep also increases the production of an immune boosting protein, cytokines, which are key in managing your immune system and help attack viruses. Sleep loss inhibits cytokine production which in turn reduces your ability to combat disease.

When sleep deprivation occurs, the production of cytokine antibodies slows, and even a modest amount of sleep loss depresses the immune system.

You can read about what happens to your immune system when you sleep in our recent article How Sleep Boosts Your Immune System.

2. Lack of Sleep Causes Weight Gain

Getting less than the recommended 7-9 hours of sleep a night, which is common for anyone suffering from insomnia, is a risk factor for weight gain and obesity. One obvious way it impacts your weight is with self control.

Have you ever stayed up late into the night and found yourself mindlessly snacking? You’re not alone, and when you aren’t choosing to stay up late but instead struggling with insomnia, that loss of will power can lead to excess pounds. Late night snacking can also lead to digestive distress that further disrupts your sleep.

One of the most profound ways sleep deprivation causes weight gain is how it affects ghrelin and leptin. These are the hormones responsible for hunger and fullness.

Ghrelin is an appetite stimulant. Leptin tells your brain when you’ve had enough to eat.

If you aren’t getting enough sleep, your brain increases the production of ghrelin and decreases leptin, leading to overeating and gaining weight.

Check out our Bedroom Diet Guide with tips and insight about how sleep deprivation can slow down your weight loss or lead to weight gain.

3. Sleep Deprivation Can Cause Hormonal Imbalances

Many, especially women, are aware of the adverse affects sex hormones can have on sleep and inducing sleep deprivation. For example, low levels of estrogen during menopause can cause the hypothalamus to raise your body temperature causing hot flashes and leading to disrupted sleep.

However, sleep deprivation or a lack of sleep can also cause hormonal imbalances. These imbalances can have widespread effects on the body. Not only are these imbalances associated with disruption of the hormones ghrelin and leptin mentioned above, but also with increased cortisol levels and impaired glucose metabolism resulting in insulin sensitivity.

Sleep deprivation can lead to hormone imbalance, and the imbalance of these hormones can lead to more sleep deprivation. It’s a vicious cycle. But with a better understanding of how your body communicates and functions is key to making necessary changes for quality sleep.

Hormones are controlled by the interactions between the hypothalamus and pituitary gland. Referred to as the master hormone system, the hypothalamic-pituitary-axis (HPA), is a complex system that combines both the endocrine and the central nervous systems.

Both your nervous system and endocrine system are major communication systems within the body. The endocrine system uses hormones to communicate while the nervous system uses chemical signals called neurotransmitters.

The relationship between your nervous system and your endocrine system is complex. How your body responds to your environment and influences your behavior results from the interactions between these two systems. If you want your body to function properly, especially your hormones, it’s vital you get good sleep, and enough of it!

Your hypothalamus controls your hormones and every vital system in your body. It essentially controls your mood, energy, memory, regulates your body temperature, and your sleep (controlling the sleep-wake cycle).

Related: How Sleep Affects Your Hormones

Melatonin and Cortisol – Two Hormones That Affect Your Sleep

Your sleep patterns are regulated by two main hormones; cortisol and melatonin.

Together, melatonin and cortisol, help support the body’s natural circadian rhythm which consists of a sleep-wake cycle most often synchronized with 24-hour daytime/nighttime period.

Cortisol levels increase peak in the morning, raising blood pressure and blood sugar, jump starting and preparing your body for the day ahead. Levels decline naturally throughout the day and drop to their lowest point around midnight.

Melatonin, also known as the “sleep hormone”, increases as external light diminishes and creates drowsiness. During the night, melatonin levels decrease while simultaneously cortisol levels increase to help suppress melatonin in the morning and prepare the body to wake.

If the balance is disrupted, and cortisol levels remain high closer to bedtime, it can lower levels of melatonin which help prepare the body for sleep. This can lead to a delayed onset of sleep.

How Stress and Cortisol Affect the Body

Nearly every cell in your body contains a receptor site for cortisol, and depending upon which cells it’s acting upon, cortisol can control your blood sugar levels, influence blood pressure, reduce melatonin levels in the body, and more.

Cortisol is a hormone that helps your body respond to stress, which is what it’s most well known for.

When you experience a stressful event, your body creates a cascade of natural responses. First it reacts by triggering the hypothalamus, which in turn signals the pituitary gland, which then signals the adrenal glands to produce the hormone cortisol.

Our reaction to a stressful situation is known as a “fight-or-flight” response. These physiological responses allowed us to fight off a threat or flee to safety. More often though they’re triggered by events and stressors that aren’t life threatening. Work challenges, family difficulties or illness can all trigger a reaction that eventually leads to chronic stress. And that stress takes a toll on your body.

Cortisol and Sleep Deprivation

Does lack of sleep cause high cortisol?

Recent studies have shown that sleep deprivation or insomnia can cause the body to release more cortisol during the day, potentially to stimulate a more alert state.

Both sleep and your stress response share the same pathway, the hypothalamic-pituitary-axis (HPA), described above as the master hormone system.

If you disrupt HPA functions, and the HPA axis is overly active, you also risk disrupting your sleep cycles. When the body is experiencing chronic or prolonged stress, the hypothalamus and pituitary gland are telling the adrenal system to produce more cortisol, creating an overly active HPA axis.

That disruption can lead to insomnia, shorter sleep time, fragmented sleep and decreased slow wave sleep1. Decreased slow wave sleep means lighter sleep and waking more often during the night. It can also affect your body’s production of cortisol, worsening the HPA axis balance.

So not only can sleep deprivation or insomnia cause high cortisol levels, but elevated cortisol can disrupt sleep and lead to insomnia.

Cortisol and Insulin Sensitivity

As mentioned earlier, cortisol is released in response to our body’s “fight or flight” response. Cortisol prepares the body for the burst of energy needed for both fight and flight by increasing blood sugar as an energy source. Cortisol slows insulin production so blood sugar won’t be stored and can be used immediately.

During a cortisol inducing stressful event you’re able to access quick energy, but insulin isn’t able to work as efficiently. If cortisol levels remain high for an extended period of time, your body can remain in an insulin-resistant state. Over time, you’re more susceptible to weight gain, chronic fatigue and diabetes, in addition to other health problems.

Sleep deprivation also contributes to elevated cortisol. Just as it is with an extended period of stress creating prolonged periods of high levels of cortisol, an extended period without or with little sleep, can have a similar effect.

When the body is unable to control blood glucose levels it can lead to prediabetes and type 2 diabetes.

In addition, stress and sleep deprivation aren’t the only things that can stimulate the production of cortisol. Sugar and refined carbohydrates eaten before bedtime also increase cortisol. So not only does the sugar increase demand for insulin, but it increases cortisol which slows insulin production.

4. Insomnia Increases Risk of Hypertension and Heart Disease

Not only is insomnia the most prevalent sleep disorder in the US, but it’s linked to the leading cause of death in the world, heart disease.

Insomnia, especially when associated with sleep deprivation, is associated with an increased risk of hypertension (high blood pressure), coronary heart disease and heart failure.

One study from Boston University School of Medicine found that anyone sleeping less than 6 hours of sleep at night had an increased prevalence of hypertension when compared to people sleeping between 7 and 8 hours per night.

Another study from the University of Arizona discovered that only one or a few poor nights of sleep can cause a sudden spike in blood pressure. The 300 participants, both men and women, had no known heart conditions prior to the study2.

5. Sleep Deprivation Causes Memory Loss

We’ve written extensively about How Sleep Deprivation is a Brain Drain.

Studies from the University of California, Berkeley showed that poor sleep could cause memory loss, forgetfulness, and brain deterioration, especially in older adults.

Certain brain waves help store memories and are responsible for transferring memories to the prefrontal cortex where long term memories are stored. The brain waves are produced during sleep, and if the memories never reach the prefrontal cortex, the long term memories are never formed which leads to forgetfulness.

Memory isn’t the only casualty of sleep deprivation. If you want to know what happens to your brain when you’re sleep deprived, check out our recent article which includes a list of side effects of short term sleep deprivation.

Sleep Disorders Are Treatable

How many of these lack of sleep side effects are you experiencing right now?

If you feel like your sleep deprivation is pointing to something more serious like chronic insomnia, you should discuss your concerns with a doctor. Sleep disorders are treatable and have serious long term health implications that may be avoided with early intervention.

If your sleep deprivation is more infrequent and you’re interested in more information about how to get a great night’s sleep, you can check out our guide for the 10 Best Ways to Optimize Your Sleep.

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  1. Arborelius L, Owens M, Plotsky P, Nemeroff C. J Endocrinol 1999;160:1-12.
  2. University of Arizona. “Sleepless nights linked to high blood pressure.” ScienceDaily. ScienceDaily, 4 June 2019. www.sciencedaily.com/releases/2019/06/190604131159.htm.
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