Sleep deprivation is a condition that occurs if you don’t get enough sleep. Sleep deficiency is a broader concept. It occurs if you have one or more of the following:
- You don’t get enough sleep (sleep deprivation)
- You sleep at the wrong time of day
- You don’t sleep well or get all the different types of sleep your body needs
- You have a sleep disorder that prevents you from getting enough sleep or causes poor-quality sleep
This topic focuses on sleep deficiency.
Sleeping is a basic human need, like eating, drinking, and breathing. Like these other needs, sleeping is vital for good health and well-being throughout your lifetime.
According to the Centers for Disease Control and Prevention, about 1 in 3 adults in the United States reported not getting enough rest or sleep every day.
Nearly 40% of adults report falling asleep during the day without meaning to at least once a month. Also, an estimated 50 to 70 million Americans have chronic, or ongoing, sleep disorders.
Sleep deficiency can lead to physical and mental health problems, injuries, loss of productivity, and even a greater likelihood of death.
What Makes You Sleep?
Your body clock
The body clock typically has a 24-hour repeating rhythm (called the circadian rhythm). Two processes interact to control this rhythm.
- The first is a pressure to sleep that builds with every hour that you’re awake. This drive for sleep peaks in the evening when most people fall asleep. A compound called adenosine seems to be one factor linked to this drive for sleep. While you’re awake, the level of adenosine in your brain continues to rise. The increasing level of this compound signals a shift toward sleep. While you sleep, your body breaks down adenosine.
- A second process involves your internal body clock. This clock is in sync with certain cues in the environment. Light, darkness, and other cues help determine when you feel awake and when you feel sleepy.
For example, light signals received through your eyes tell your brain that it is daytime. This area of your brain helps align your body clock with periods of the day and night.
Your body releases chemicals in a daily rhythm that your body clock controls.
When it gets dark, your body releases a hormone called melatonin. Melatonin signals your body that it’s time to prepare for sleep, and it helps you feel sleepy.
The amount of melatonin in your bloodstream peaks as the evening passes. Researchers believe this peak is an important part of preparing your body for sleep.
Exposure to bright artificial light late in the evening can disrupt this process, making it hard to fall asleep. Examples of bright artificial light include the light from a TV screen, computer screen, or a very bright alarm clock.
As the sun rises, your body releases cortisol. This hormone naturally prepares your body to wake up.
Changes in body clock with aging
The rhythm and timing of the body clock change with age. Teens fall asleep later at night than younger children and adults. One reason for this is because melatonin is released and peaks later in the 24-hour cycle for teens. As a result, it’s natural for many teens to prefer later bedtimes at night and sleep later in the morning than adults.
People also need more sleep early in life when they’re growing and developing. For example, newborns may sleep more than 16 hours a day, and preschool-age children need to take naps.
Young children tend to sleep more in the early evening. Teens tend to sleep more in the morning. Also, older adults tend to go to bed earlier and wake up earlier.
The patterns and types of sleep also change as people mature. For example, newborn infants spend more time in REM (rapid eye movement) sleep. Dreaming typically occurs during REM sleep.
The amount of deep or slow-wave sleep (non-REM sleep) peaks in early childhood and then drops sharply after puberty. It continues to decline as people age.
How do I know if I’m not getting enough sleep?
Sleep deficiency can cause you to feel very tired during the day. You may not feel refreshed and alert when you wake up. Sleep deficiency also can interfere with work, school, driving, and social functioning.
How sleepy you feel during the day can help you figure out whether you’re having symptoms of problem sleepiness.
You might be sleep deficient if you often feel like you could doze off while:
- Sitting and reading or watching TV
- Sitting still in a public place, such as a movie theater, meeting, or classroom
- Riding in a car for an hour without stopping
- Sitting and talking to someone
- Sitting quietly after lunch
- Sitting in traffic for a few minutes
Sleep deficiency can cause problems with learning, focusing, and reacting. You may have trouble making decisions, solving problems, remembering things, managing your emotions and behavior, and coping with change. You may take longer to finish tasks, have a slower reaction time, and make more mistakes.
Symptoms in children
The symptoms of sleep deficiency may differ between children and adults. Children who are sleep deficient might be overly active and have problems paying attention. They also might misbehave, and their school performance can suffer.
Sleep-deficient children may feel angry and impulsive, have mood swings, feel sad or depressed, or lack motivation.
Sleep and your health
The way you feel while you’re awake depends in part on what happens while you’re sleeping. During sleep, your body is working to support healthy brain function and support your physical health. In children and teens, sleep also helps support growth and development.
The damage from sleep deficiency can happen in an instant (such as a car crash), or it can harm you over time. For example, ongoing sleep deficiency can raise your risk of some chronic health problems. It also can affect how well you think, react, work, learn, and get along with others.
Mental health benefits
Sleep helps your brain work properly. While you’re sleeping, your brain is getting ready for the next day. It’s forming new pathways to help you learn and remember information.
Studies show that a good night’s sleep improves learning and problem-solving skills. Sleep also helps you pay attention, make decisions, and be creative.
Studies also show that sleep deficiency changes activity in some parts of the brain. If you’re sleep deficient, you may have trouble making decisions, solving problems, controlling your emotions and behavior, and coping with change. Sleep deficiency has also been linked to depression, suicide, and risk-taking behavior.
Children and teens who are sleep deficient may have problems getting along with others. They may feel angry and impulsive, have mood swings, feel sad or depressed, or lack motivation. They also may have problems paying attention, and they may get lower grades and feel stressed.
Physical health benefits
Sleep plays an important role in your physical health.
- Heals and repairs your heart and blood vessels.
- Helps support a healthy balance of the hormones that make you feel hungry (ghrelin) or full (leptin): When you don’t get enough sleep, your level of ghrelin goes up and your level of leptin goes down. This makes you feel hungrier than when you’re well-rested.
- Affects how your body reacts to insulin: Insulin is the hormone that controls your blood glucose (sugar) level. Sleep deficiency results in a higher-than-normal blood sugar level, which may raise your risk of diabetes.
- Supports healthy growth and development: Deep sleep triggers the body to release the hormone that promotes normal growth in children and teens. This hormone also boosts muscle mass and helps repair cells and tissues in children, teens, and adults. Sleep also plays a role in puberty and fertility.
- Affects your body’s ability to fight germs and sickness: Ongoing sleep deficiency can change the way your body’s natural defense against germs and sickness responds. For example, if you’re sleep deficient, you may have trouble fighting common infections.
- Decreases your risk of health problems, including heart disease, high blood pressure, obesity, and stroke.
Daytime performance and safety
Getting enough quality sleep at the right times helps you function well throughout the day. People who are sleep deficient are less productive at work and school. They take longer to finish tasks, have a slower reaction time, and make more mistakes.
After several nights of losing sleep — even a loss of just 1 to 2 hours per night — your ability to function suffers as if you haven’t slept at all for a day or two.
Lack of sleep also may lead to microsleep. Microsleep refers to brief moments of sleep that happen when you’re normally awake.
You can’t control microsleep, and you might not be aware of it. For example, have you ever driven somewhere and then not remembered part of the trip? If so, you may have experienced microsleep.
Even if you’re not driving, microsleep can affect how you function. If you’re listening to a lecture, for example, you might miss some of the information or feel like you don’t understand the point. You may have slept through part of the lecture and not realized it.
Some people aren’t aware of the risks of sleep deficiency. In fact, they may not even realize that they’re sleep deficient. Even with limited or poor-quality sleep, they may still think they can function well.
For example, sleepy drivers may feel able to drive. Yet studies show that sleep deficiency harms your driving ability as much or more than being drunk. It’s estimated that driver sleepiness is a factor in about 100,000 car accidents each year, resulting in about 1,500 deaths.
Drivers aren’t the only ones affected by sleep deficiency. It can affect people in all lines of work, including healthcare workers, pilots, students, lawyers, mechanics, and assembly line workers.
How Much Sleep Is Enough
The amount of sleep you need each day will change over the course of your life. Although sleep needs vary from person to person, the chart below shows general recommendations for different age groups. This table reflects American Academy of Sleep Medicine (AASM) recommendations that the American Academy of Pediatrics (AAP) has endorsed.
|Age||Recommended Amount of Sleep|
|Newborns 4 to 12 months||12 to 16 hours a day (including naps)|
|Children 1 to 2 years old||11 to 14 hours a day (including naps)|
|Children 3 to 5 years old||10 to 13 hours a day (including naps)|
|Children 6 to 12 years old||9 to 12 hours a day|
|Teens 13 to 18 years old||8 to 10 hours a day|
|Adults 18 years or older||7 to 8 hours a day|
If you regularly lose sleep or choose to sleep less than needed, the sleep loss adds up. The total sleep lost is called your sleep debt. For example, if you lose 2 hours of sleep each night, you’ll have a sleep debt of 14 hours after a week.
Some people nap to deal with sleepiness. Naps may give a short-term boost in alertness and performance. However, napping doesn’t supply all the other benefits of nighttime sleep, so you can’t really make up for lost sleep.
Some people sleep more on their days off than on workdays. They also may go to bed and wake up later on days off.
Sleeping more on days off might be a sign that you aren’t getting enough sleep. Although extra sleep on days off might help you feel better, it can upset your body’s sleep-wake rhythm.
Who is at risk of sleep deprivation and deficiency?
Sleep deficiency, which includes sleep deprivation, affects people of all ages, races, and ethnicities. Certain groups of people may be more likely to be sleep deficient, including people who:
- Have limited time for sleep, such as caregivers or people working long hours or more than one job
- Have schedules that conflict with their internal body clocks, such as shift workers, first responders, teens who have early school schedules, or people who must travel for work
- Make lifestyle choices that prevent them from getting enough sleep, such as taking medicine to stay awake, misusing alcohol or drugs, or not leaving enough time for sleep
- Have undiagnosed or untreated medical problems, such as stress, anxiety, or sleep disorders
- Have medical conditions or take medicines that interfere with sleep
If your job or daily routine limits your ability to get enough sleep or sleep at the right times, talk with your doctor. You also should talk with your doctor if you sleep more than 8 hours a night, but don’t feel well rested. You may have a sleep disorder or other health problem.
Healthy Sleep Habits
You can take steps to improve your sleep habits. First, make sure that you give yourself enough time to sleep. With enough sleep each night, you may find that you’re happier and more productive during the day.
Sleep is often the first thing that busy people squeeze out of their schedules. Making time to sleep will help you protect your health and well-being now and in the future.
To improve your sleep habits, it also may help to:
- Go to bed and wake up at the same time every day. For children, have a set bedtime and a bedtime routine. Don’t use the child’s bedroom for timeouts or punishment.
- Try to keep the same sleep schedule on weeknights and weekends. Limit the difference to no more than about an hour. Staying up late and sleeping in late on weekends can disrupt your body clock’s sleep-wake rhythm.
- Use the hour before bed for quiet time. Avoid intense exercise and bright artificial light, such as from a TV or computer screen. The light may signal the brain that it’s time to be awake.
- Avoid heavy or large meals within a few hours of bedtime. (Having a light snack is okay.) Also, avoid alcoholic drinks before bed.
- Avoid nicotine (for example, cigarettes) and caffeine (including caffeinated soda, coffee, tea, and chocolate). Nicotine and caffeine are stimulants, and both substances can interfere with sleep. The effects of caffeine can last up to 8 hours. So, a cup of coffee in the late afternoon can make it hard for you to fall asleep at night.
- Spend time outside every day (when possible) and be physically active.
- Keep your bedroom quiet, cool, and dark (a dim night light is fine, if needed).
- Take a hot bath or use relaxation techniques before bed.
Napping during the day may boost your alertness and performance. However, if you have trouble falling asleep at night, limit naps or take them earlier in the afternoon. Adults should nap for no more than 20 minutes.
Napping in preschool-age children is normal and promotes healthy growth and development.
Strategies for shift workers
Some people have schedules that conflict with their internal body clocks. For example, shift workers may have trouble getting enough sleep. This can affect how they feel mentally and physically.
If you’re a shift worker, you may find it helpful to:
- Take naps and raise the amount of time available for sleep
- Keep the lights bright at work
- Limit shift changes so your body clock can adjust
- Limit caffeine use to the first part of your shift
- Remove sound and light distractions in your bedroom during daytime sleep (for example, use light-blocking curtains)
If you’re still not able to fall asleep during the day or have problems adapting to a shift-work schedule, talk with your doctor about other options to help you sleep.