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How Can You Tell If You Have Sleep Deprivation

Find out what bad impacts it can have on your health and safety.
Published on January 21, 2025

Sleep deprivation is a condition you can develop if you don’t get the amount of sleep your body needs. The most noticeable sign you have sleep deprivation is that you feel fatigued during the daytime. That fatigue can negatively impact how you function and how alert you are during the day, which can be dangerous.

But the consequences of sleep deprivation can go beyond just a day of being tired. If continued, sleep deprivation can have long-term consequences for your health.

Recognizing and addressing the lack of sleep can help you avoid the mental, physical, and safety risks sleep deprivation can cause.

How Much Sleep Do You Need?

The general rule of thumb is that most adults need at least seven hours of sleep per night. This amount of sleep can help you feel rested and keep your mind and body functioning properly.

However, the ideal amount of sleep time can vary from person to person and is based on several factors, like age, lifestyle, overall health, genetics, and how much sleep you’ve been getting lately. In other words, some adults may feel they can function on a little less than the recommended seven hours, while others may need up to nine hours to feel refreshed the next day.

Children need even more sleep. Teenagers need 8-10 hours of sleep a night, while school-aged children need 9-12. Younger children need more sleep, spread throughout the day. For instance, toddlers should get 11-14 hours of sleep a day, including naps.

At What Point Is Lack of Sleep Considered Sleep Deprivation?

Getting any amount of rest less than what you need could be considered sleep deprivation. In a study setting, researchers may use specific amounts of sleep to define sleep deprivation.

Some research has used 24 hours of no sleep as the marker for what’s considered sleep deprivation. Other researchers label a night of no sleep as total sleep deprivation and several nights in a row of four hours of sleep as partial sleep deprivation. Over time, partial sleep deprivation can have the same effect as total sleep deprivation.

Sometimes, it can be the quality and not the quantity of sleep that causes you to develop sleep deprivation. You can technically get the amount of sleep that’s right for you and still be sleep-deprived the next day if your sleep quality was poor. Factors like the number of times you wake up in the middle of the night and how long you are in each stage of sleep dictate your sleep quality.

The effects of sleep deprivation can kick in quickly. Research shows that just one night of too little sleep is enough to throw you off mentally and physically the next day. Unfortunately, these effects might not be too uncommon, as it’s estimated that roughly a third of adults in the U.S. don’t get enough sleep.

What Are Signs of Sleep Deprivation?

Most noticeably, being sleep-deprived means you feel fatigued the following day. This means you will feel tired and exhausted.

Fatigue can negatively affect your ability to function physically and mentally. Your behavior and mood might change, as well. Specific signs of sleep deprivation include:

  • An inability to focus
  • Slower physical and mental reaction times
  • Headaches
  • Clumsiness
  • Forgetfulness
  • Irritability
  • Lack of motivation
  • Moodiness
  • Trouble concentrating
  • Lower sex drive

Being less willing to do tasks could be a sign of sleep deprivation, too. Research has shown that people who are fatigued from sleep deprivation consider tasks to be harder than they might actually be. For instance, a walk might seem longer than it actually is, and so you’d choose to not go on the walk.

If you are sleep-deprived, you’ll likely find that the next time you sleep will be longer and deeper. You’ll also probably be able to fall asleep very quickly.

Children might experience sleep deprivation differently. Children who don’t get enough sleep might be overly active. Similar to adults, children might also have problems focusing. Their school performance might drop, and they might act up more.

Symptoms at Different Stages of Sleep Deprivation

The human body operates on a 24-hour cycle, so sleep deprivation can manifest as soon as the next day after sleep loss. From there, the side effects can get worse as time goes on:

One day after no sleep, you’ll probably notice some of the general signs of sleep deprivation, like drowsiness, irritability, fatigue, headache, and trouble concentrating. Being awake for this long without sleep has been compared to having a blood alcohol concentration level of 0.10%.

Fast forward to 36 hours without sleep, and the body’s energy levels may be drastically lower. It’s possible to experience anger, anxiousness, or confusion. You may also feel disoriented or detached.

After 48 hours without sleep, you can begin to have hallucinations. Other sleep deprivation symptoms start to get worse, and the body is likely weak.

Reaching 72 hours of not sleeping can involve severe symptoms like more intense hallucinations and possibly psychosis (seeing and hearing things that are not there). In addition, feelings of paranoia and delusion can be present.

What Causes Sleep Deprivation?

There could be many reasons why you are not getting the amount of sleep you need. This includes sleep disorders like sleep apnea (when your breathing pauses as you sleep), insomnia (when you have trouble falling or staying asleep), and restless legs syndrome (when you feel the need to move your legs when you are resting).

Other medical conditions that are not sleep-related can also disrupt your sleep. Arthritis, back pain, heart disease, asthma, depression, anxiety, and substance abuse can all make it harder for you to get the quality deep sleep you need.

Lifestyle factors like having work or social activities at night can create the opportunity for sleep deprivation. Sleeping in a room that is too loud, bright, hot, or cold can affect your sleep, as well.

Stressing about your sleep can negatively impact how much sleep you get, too.

Risks of Sleep Deprivation

Sleep is essential for restoring the brain and body in many different ways, so not getting enough of it on a regular basis can impact your physical and mental health.

Some of the short-term consequences of sleep deprivation include:

  • Impaired decision-making
  • Higher risk of being in or causing a car accident
  • Risk of being involved in a work accident or sustaining an injury, particularly for shift workers
  • Issues with memory function
  • Hunger and weight gain
  • Vision issues
  • Emotional outbursts
  • Impulsivity

Over time, repeated sleep deprivation can take a toll on your body and health in the following ways:

  • Weakened immune system
  • Increased risk for developing type 2 diabetes
  • Elevated blood pressure
  • Higher risk of heart attacks
  • Increased risk for mental health conditions like depression, anxiety, or other mood disorders

Chronic sleep deprivation can also negatively affect your quality of life. This may be because your fatigue prevents you from being able to do things you enjoy or because your sleepiness strains your work or home life.

When to Contact a Healthcare Provider

Experiencing a sleepless night every now and again isn’t necessarily a cause for alarm.

But if you find yourself routinely feeling tired during the day or unable to carry out daily activities due to a lack of sleep, it may be time to check with a healthcare provider.

Whether it’s a sleep disorder like insomnia or sleep apnea or lifestyle circumstances preventing you from getting the recommended amount of sleep, a healthcare provider can help you get to the bottom of the issue.

How Is Sleep Deprivation Diagnosed?

Hearing about your sleep habits, medical history, and current symptoms can help a healthcare provider diagnose sleep deprivation and any underlying medical conditions that may be causing it.

In addition to a physical exam and potential blood tests to rule out other issues that could cause sleep problems, be prepared to answer questions like:

  • What time do you go to bed and wake up?
  • How long have you been having trouble sleeping?
  • How long does it generally take you to fall asleep?
  • Do you wake up in the middle of the night?
  • Do you feel fully refreshed and rested in the morning?
  • How often do you feel like dozing off during the day?
  • Have you experienced a recent change in schedule or life circumstances?

You’ll also want to share any details about your work and exercise routines plus any medications or substances (including alcohol, caffeine, and tobacco) you may be consuming.

Sometimes, a referral to a sleep specialist may be necessary. They might use a sleep study—known as polysomnography—to help diagnose a sleep disorder like sleep apnea. This type of test records brain waves, monitors various vital signs and keeps track of your body’s movements during a full night’s sleep.

How Do You Fix Sleep Deprivation?

Sleep deprivation symptoms will typically go away once you start getting the right amount of sleep. However, fixing sleep deprivation isn’t always as easy as just getting a lot of sleep one night. Sleep patterns are complicated, and it can take time to readjust to a new one.

To avoid feeling overwhelmed, start by figuring out the amount of sleep you personally need to feel rested. Then, plan ahead for sleep interruptions you expect you might have, such as late nights or early mornings.

From there, it may be helpful to clean up your sleep hygiene routine. Some expert-recommended tips to get your sleep habits back on track include:

  • Going to bed and waking up at the same time every day, including on weekends
  • Avoiding caffeine, alcohol, and large meals in the later part of the day
  • Exercising regularly, but not too close to bedtime
  • Limiting screen time in the evening
  • Relaxing before it’s time to go to sleep, whether by reading, taking a bath, or listening to calm music
  • Keeping the room temperature cool
  • Getting enough exposure to sunlight during the daytime

If the underlying cause of your sleep deprivation is a sleep disorder or another health condition, a healthcare provider can recommend a specific treatment plan. This might involve an over-the-counter or prescription sleep aid, cognitive behavioral therapy (CBT) for insomnia, or a continuous positive airway pressure (CPAP) machine for people with sleep apnea.

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