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Lack of Sleep? Key Causes and Effects of Sleep Deprivation

Lack of Sleep: Key Causes and Effects of Sleep Deprivation

Continual lack of sleep — also known as sleep deprivation — can take its toll on your everyday life. Impacts can range from decreased cognitive performance to increases in stress and anxiety and even the development of more serious health conditions.

However, while poor sleep can be frustrating at times, there are steps you can take to overcome it. To help get to the bottom of your sleeplessness, we’ll take a deeper look at the key causes and effects of sleep deprivation, and offer some ways to tackle them.

What is sleep deprivation?

Put simply, sleep deprivation refers to a continued or chronic lack of sleep. While sleep requirements vary from person to person, it’s widely accepted that most healthy adults need 7-9 hours of sleep to support their overall wellness. Obtaining less than this regularly can lead to several problems, from compromised cognition and weakened immunity to low mood and poor concentration.

What causes sleep deprivation?

For some people, sleep is considered wasted time. As a result, many unconsciously deprive themselves of quality rest to pursue occupational goals,  educational ventures, or entertainment — as seen by the rise in late-night screen-use. Others may become sleep deprived because of lifestyle factors such as family responsibilities, shift work, or stress.
Additional causes of sleep deprivation often include poor diet choices — such as drinking too much caffeine or alcohol — hormonal imbalances, chronic illnesses and even sleep disorders that can disrupt rest.

What are the effects of sleep deprivation?

Increased appetite and weight gain

If your brain doesn’t get the nourishment it needs from sleep, it will turn to food. Poor sleep not only accelerates the production of the hormone, ghrelin, which increases appetite, but it also suppresses its leptin – the hormone that signals food satisfaction. What's more, one study found that surviving on four and a half hours’ sleep for four days could diminish your fat cells’ ability to respond to insulin — the hormone that regulates energy — by 30%.iii

With an increased appetite, you may experience another by-product of sleep deprivation: weight gain. Feeling low on energy from a lack of sleep, you’ll likely crave unhealthy treats and refined carbs to keep you going throughout the day.

Reduced problem-solving ability

Sleep deprivation affects your speed and cognitive processing, which, in turn, can impact your time management and problem-solving skills. In one study, researchers instructed both well-rested and sleep-deprived volunteers to carry out a set of tasks that demanded speedy decision-making. In between testing, the accuracy of participants without quality sleep depreciated by 2.4%, while their rested counterparts improved by 4.3%.iv As this study demonstrates, insufficient sleep impedes your cognitive functioning, alertness, and ability to respond to tasks quickly.

Mental health

Scientists are still unsure why rapid-eye-movement (REM) sleep — when dreams occur, memories are stored and learning is consolidated — is so restorative for our brains and bodies. One theory is that norepinephrine, a chemical associated with stress, isn’t secreted during REM sleep. The ‘REM calibration hypothesis’ proposes that REM sleep can reset the levels of norepinephrine, thereby making the brain less reactive and sensitive to emotional stimuli.v
If your norepinephrine levels are disrupted, you might find your mental health is impacted, making you more vulnerable to stress and anxiety. Understanding how stress and anxiety can disrupt your sleep could be the key to overcoming it.

Weaker immune system

Sleep deprivation could also lead to more sick days. Without enough quality rest, your immune cells and proteins of your immune system are negatively affected, paving the way for colds, flu, and other infections. Even one night of reduced sleep can significantly disrupt your body’s That’s why, when illness strikes, your first instinct is to get back under the covers. Your body is attempting to sleep itself better.

Problem skin

When you sleep, your skin works tirelessly to repair and rejuvenate any damaged skin cells.  But insufficient sleep can disrupt this process — it skews the delicate hormonal balance and increases levels of circulating oestrogen, leading to more breakouts and fine lines. In a 2013 trial, researchers discovered that skin recovery was 30% higher in participants who had better sleep quality than those with insufficient sleep.vii

We all need enough sleep to function properly — it’s one of the simplest steps we can take towards better overall health. To discover more ways to achieve a restful night’s sleep, simply visit our dedicated sleep hub.



  1. 'Sleep should be prescribed': what those late nights out could be costing you. The Guardian. Available online:

  2. The Independent. Average Briton gets six hours and 19 minutes of sleep a night, study finds. Available online:

  3. , , , & Impaired Insulin Signaling in Human Adipocytes After Experimental Sleep Restriction. Annals of Internal Medicine.157(8), p.549.

  4. , , , , , & The Effects of Sleep Deprivation on Information-Integration Categorization Performance. Sleep. 32(11), pp.1439-1448.

  5. , , & The A role for REM sleep in recalibrating the sensitivity of the human brain to specific emotions. Cerebral cortex (New York, N.Y. : 1991). 21(1), 115–123.

  6. , , , & Sleep Habits and Susceptibility to the Common Cold. Archives of Internal Medicine. 169(1), 62.

  7. Estée Lauder Clinical Trial Finds Link between Sleep Deprivation and Skin Aging. Available online:


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Our Author - Olivia Salter


Olivia Salter has always been an avid health nut. After graduating from the University of Bristol, she began working for a nutritional consultancy where she discovered her passion for all things wellness-related. There, she executed much of the company’s content marketing strategy and found her niche in health writing, publishing articles in Women’s Health, Mind Body Green, Thrive and Psychologies.

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