Why Is Sleep Important?
Sleep plays a vital role in good health and well-being throughout your life. Getting enough quality sleep at the right times can help protect your mental health, physical health, quality of life, and safety.
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 maintain your physical health. In children and teens, sleep also helps support growth and development.
The damage from sleep deficiency can occur in an instant (such as a car crash), or it can harm you over time. For example, ongoing sleep deficiency can raise your risk for some chronic health problems. It also can affect how well you think, react, work, learn, and get along with others.
Healthy Brain Function and Emotional Well-Being
Sleep helps your brain work properly. While you're sleeping, your brain is preparing 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. Whether you're learning math, how to play the piano, how to perfect your golf swing, or how to drive a car, sleep helps enhance your learning and problem-solving skills. Sleep also helps you pay attention, make decisions, and be creative.
Studies also show that sleep deficiency alters activity in some parts of the brain. If you are sleep-deficient, you may have trouble making decisions, solving problems, controlling your emotions and behavior, and coping with change. Sleep deficiency also has 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
Sleep plays a key role in physical health. For example, sleep is involved in healing and repair of your heart and blood vessels. Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, diabetes, and stroke.
Sleep deficiency also increases the risk of obesity. For example, one study of teenagers showed that with each hour of sleep lost, the odds of becoming obese went up. Sleep deficiency increases the risk of obesity in other age groups as well.
Sleep helps maintain 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.
Sleep also affects how your body reacts to insulin, the hormone that controls your blood glucose (sugar) level. Sleep deficiency results in a higher than normal blood sugar level, which may increase your risk for diabetes.
Sleep also 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.
Your immune system relies on sleep to stay healthy. This system defends your body against foreign or harmful substances. Ongoing sleep deficiency can change the way in which your immune system responds. For example, if you are sleep-deficient, you may have trouble fighting common infections.
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 the recent American Academy of Sleep Medicine (AASM) recommendations that the American Academy of Pediatrics (AAP) has endorsed.
| Age | Recommended Amount of Sleep |
| Infants aged 4-12 months | 12-16 hours a day (including naps) |
| Children aged 1-2 years | 11-14 hours a day (including naps) |
| Children aged 3-5 years | 10-13 hours a day (including naps) |
| Children aged 6-12 years | 9-12 hours a day |
| Teens aged 13-18 years | 8-10 hours a day |
| Adults aged 18 years or older | 7–8 hours a day |
If you routinely 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 provide a short-term boost in alertness and performance. However, napping doesn't provide all the other benefits of night-time sleep. Thus, 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 later and get up later 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.
Bad sleep habits and long-term sleep loss will affect your health. If you're worried about whether you're getting enough sleep, try using a sleep diary for a couple of weeks.
For more information visit https://www.nhlbi.nih.gov/health/health-topics/topics/sdd/why.
