Sleep deprivation: symptoms, effects, stages

last updated: Jun 08, 2021

6 min read

Sleep is essential for survival. Without it, our minds and bodies begin to suffer. Sleep deprivation not only affects our functioning after a night of poor sleep, but it can also cause long-term health consequences and significant safety concerns.

Before you let Netflix talk you into just one more episode, here’s what you should know about sleep deprivation and why you should make getting better sleep a top priority. 


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What is sleep deprivation?

Sleep deprivation is when you don’t get enough sleep. For adults, the American Academy of Sleep Medicine recommends at least seven hours of sleep each night (Consensus Conference Panel, 2015). Unfortunately, about one-third of adults in the United States report getting less than this, a problem that’s only gotten worse over the last several years (CDC, 2017; Sheehan, 2019). Researchers believe increasing work demands and 24/7 access to television and the internet have contributed to the rise in sleep problems (Hanson, 2021). 

Sleep deprivation can be acute or chronic. Acute or total sleep deprivation refers to not sleeping at all for a prolonged period—like pulling all-nighters to study for an exam or complete a project due at work. Chronic or partial sleep deprivation occurs when you consistently sleep less than the recommended amount, night after night (Krause, 2017). 

Sleep deprivation is different from insomnia, although insomnia can undoubtedly cause a lack of sleep. People who experience insomnia have difficulty falling asleep or staying asleep, even if they have plenty of time to rest. People with sleep deprivation will often fall asleep quickly if given the opportunity (Kaur, 2020). 

Who’s at risk for sleep deprivation?

Sleep loss can occur for various reasons, including social and occupational factors, psychological stressors, or medical conditions (Medic, 2017). Some of these factors may be things that you can change, such as limiting your caffeine intake or blocking out bright light from your bedroom. Other factors may be more permanent and require strategies that focus instead on optimizing your sleep habits. 

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People who have jobs that involve shift work can experience alterations in their circadian rhythm—the body’s internal control over the sleep-wake cycle (Medic, 2017).

Your circadian rhythm attempts to sync your body’s sleep schedule to match the environmental light-dark cycles of a typical day. Light sensors in the eye send signals to the part of the brain that controls your circadian rhythm. One response is the release of melatonin at night when it’s dark, which helps your body prepare to sleep (Colten, 2006).

Unfortunately, people who work the night shift must sleep during the day, which your body views as unnatural. For this reason, shift-workers often have difficulty getting an adequate amount of sleep (Medic, 2017). 

Sleep deprivation symptoms 

The most common symptom of sleep deprivation is daytime sleepiness. You may also experience (Hanson, 2021): 

  • Difficulty concentrating 

  • Impaired memory 

  • Mood changes, such as feeling anxious, depressed, or irritable 

  • Trouble staying focused 

Sleep deprivation can also cause microsleep. Microsleep is a term that refers to extremely short periods of sleep that interrupt normal wake times (Des Champs de Boishebert, 2021).

Have you ever been driving and suddenly not recalled how you got from point A to point B? Or have you ever sat through a lecture and felt like your brain blocked out the last few minutes? If so, you may have experienced microsleep. Microsleeps impair your ability to respond and may even cause your eyelids to close and your head to nod. The effects of microsleep can be hazardous if you’re driving or working in a profession requiring constant attention, such as being a pilot or surgeon (Poudel, 2014). 

Sleep deprivation stages

Acute sleep deprivation (staying awake, without any sleep, for a prolonged period) can cause symptoms that affect your perception of reality, including sleep deprivation hallucinations. While there are no formal stages of sleep deprivation, certain symptoms tend to appear depending on the length of time you’ve been awake. Researchers have observed the following unique symptoms (Waters, 2018): 

Awake for 24 hours: 

  • Anxiety or irritability 

  • Visual distortions: Objects may appear larger or smaller than their actual size, stationary objects appear to move, or colors become lighter or darker. 

  • Double vision 

Awake for 25–48 hours:

  • Altered sense of time: Time may feel like it is passing slowly. 

  • Visual illusions: Objects transform into something different (like a jacket becoming a chair). 

  • Simple visual hallucinations: These can include experiences like seeing an undefined substance growing on the floor or the appearance of geometric shapes. 

  • Disordered thoughts

Awake for 49–72 hours:

  • Depression or euphoria (intense happiness or excitement)

  • Complex visual hallucinations: Fully formed figures can appear, such as people, animals, or other objects. 

  • Auditory hallucinations: You may hear voices or sounds (like a dog barking) that are not there.  

Awake for more than 72 hours:

  • Delusions: You may start to believe things that aren’t true. For example, a delusion can involve believing someone is plotting against you or that you are receiving a special message through the television. 

Effects of sleep deprivation 

Sleep deprivation can have a significant impact on your physical health and mental wellbeing. People with chronic sleep deprivation report a lower quality of life when asked about their ability to function throughout the day, their physical and mental health, and their social functioning (Hanson, 2021). 

Despite being pushed by some lifestyle gurus and sounding quite appealing to many, the idea that you can simply adjust to less sleep is not true. Insufficient sleep alters chemicals in your body resulting in several negative outcomes.

For example, chronic sleep deprivation causes an increase in cortisol—a stress hormone involved in many processes in your body. People with high cortisol levels may be at increased risk of depression, anxiety, and high blood pressure. Cortisol also increases blood sugar and cravings for carbohydrates and sugar. This can lead to weight gain, obesity, and diabetes (Hanson, 2021). 

Not getting enough sleep also causes appetite-regulating hormones, particularly leptin and ghrelin, to get out of whack. Leptin suppresses appetite, while ghrelin makes you hungry (Colten, 2006). Chronic sleep deprivation can cause lower levels of leptin and higher levels of ghrelin, leading many people to overeat and gain weight (Nedeltcheva, 2014). Together, these can further increase your risk of heart disease and other health problems. 

Chronically sleep-deprived people have a higher chance of developing the following conditions (Consensus Conference Panel, 2015; Hanson, 2021):

  • Anxiety

  • Depression

  • Diabetes or impaired blood glucose control 

  • Heart attack 

  • High blood pressure 

  • Impaired immune system functioning 

  • Increased risk of death 

  • Increased pain 

  • Obesity

  • Obstructive sleep apnea

  • Psychosis

  • Stroke

Safety is another concern when you’re sleep-deprived. Lack of sleep can slow your reaction time and affect your judgment and decision-making abilities (Colten, 2006). What’s worse is that people often underestimate their degree of impairment and feel like they can function normally (Basner, 2013).  

In addition to impacting you, these effects can also impact other people, especially if your job requires constant attention and accuracy, such as being a pilot, air traffic controller, healthcare professional, or machine worker.

Driving while tired, also called “drowsy driving,” can be just as dangerous as drunk driving. One study comparing sleep-deprived drivers with those that had consumed alcohol showed similar levels of impaired driving performance. These results translate into real-world experience since approximately 20% of all serious car crash injuries are associated with driver sleepiness (Colten, 2006).  

Diagnosis of sleep deprivation 

Your healthcare provider will likely be able to diagnose you with sleep deprivation based on your symptoms alone. They may ask you to keep a sleep diary to collect information on your sleep patterns. This can be done on paper or by using a sleep diary app on your phone. The information you record will likely include (Carney, 2012):

  • What time you got into bed

  • The time you fell asleep

  • How often you woke up and for how long

  • The time you got out of bed in the morning

  • The overall rating of your quality of sleep  

Actigraphy is another tool healthcare providers use to monitor your sleep. Actigraphy uses a device (typically worn on the wrist) to record movement and estimate total sleep time. This can be helpful if you're having difficulty completing a sleep diary (Smith, 2016). The devices used for actigraphy are different from a smartwatch, although many smart devices have some degree of sleep-tracking ability. 

A sleep study offers even more information about your body and brain function during sleep. While not needed for most people, your healthcare provider may recommend you complete a sleep study if they suspect you have a sleep disorder contributing to your symptoms, such as obstructive sleep apnea. A sleep study typically involves spending the night in a sleep center or hospital. A technician places painless sensors on your head and body that collect information while you sleep. Your healthcare provider will use this information to help diagnose any sleep condition you may have (Gerstenslager, 2020). 

Treating and preventing sleep deprivation 

Improving the amount and quality of your sleep is key to preventing and treating sleep deprivation. Healthcare providers often recommend focusing on sleep hygiene—a set of behaviors and environmental changes that promote healthy sleep (Irish, 2015). 

Follow these tips for a good night’s sleep:

  • Avoid alcohol close to bedtime. Alcohol can make it easier to fall asleep, but it reduces sleep quality (Irish, 2015). 

  • Avoid excess caffeine, especially later in the day (Irish, 2015). 

  • Exercise daily. Studies have shown that regular physical activity can help you fall asleep faster, stay asleep, and improve sleep quality (Kredlow, 2015). 

  • Go to sleep and wake up at the same time each day, even on the weekends (Maness, 2015). 

  • Maintain a comfortable sleep environment, free of excess noise and light. Room-darkening curtains, earplugs, and a white noise machine can help (Maness, 2015). 

If your healthcare provider suspects your symptoms are due to a sleep disorder, they may recommend seeing a sleep specialist. Treating the underlying cause of your sleep deprivation will provide the best outcomes. Healthcare providers don’t typically prescribe sleep medications initially since they have side effects that can worsen some sleep conditions, such as obstructive sleep apnea (Hanson, 2021). 

If you’re not getting enough sleep, getting through the day can be a challenge. Your personal and professional responsibilities may seem overwhelming when you’ve only had a little sleep. Talk with your healthcare professional about any concerns you have regarding your sleep health. Together you can develop a plan that gets you sleeping better and on your way to feeling your best. 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Current version

June 08, 2021

Written by

Christina Varvatsis, PharmD

Fact checked by

Steve Silvestro, MD

About the medical reviewer

Dr. Steve Silvestro is a board-certified pediatrician and Associate Director, Clinical Content & Education at Ro.