Sleep Deprivation and Deficiency How Sleep Affects Your Health
Getting enough quality sleep at the right times can help protect your mental health, physical health, quality of life, and safety.
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.