What is sleep?

You may think that nothing happens during sleep – but in reality, your brain and body are very active as you sleep.

There are two kinds of sleep, and they affect your body and mind in different ways.

• NREM sleep – If you’re lucky, you fall asleep within ten to 20 minutes of going to bed. Then your body begins its sleep cycle. The first four stages are non-rapid eye movement (NREM). Stages 1 and 2 are light sleep; you can be awakened easily and muscle contractions can be seen. In stages 3 and 4 the brain waves slow and you enter into deep sleep. There’s no eye movement or muscle activity at this point.
• REM sleep and dreaming – The fifth stage of sleep normally occurs after about 90 minutes and is characterized by dreaming and rapid eye movement (REM). No other muscles move during this time. If you have the chance to watch a friend or family member sleep, check to see if their eyes are moving back and forth, like they’re watching a movie beneath closed eyelids. If so, they’re likely in the middle of a dream.

The NREM and REM sleep cycles repeat throughout the night. The first period of dreaming only lasts five minutes and lengthen with each subsequent cycle. People typically spend more than two hours each night dreaming.

How much sleep do you need and why?

Most teenagers need eight to ten hours of sleep per day. Yet surveys from the Centers for Disease Control and Prevention (CDC) show that, on average, 7 out of 10 teens get less than eight hours of sleep on school nights.

If you don’t get enough sleep, you may experience symptoms of sleep deprivation. These include:

• Falling asleep in class.
• Irritability.
• Difficulty waking up in the morning.
• Difficulty concentrating.
• Depression after prolonged sleep deprivation.

Sleep keeps you healthy in many other ways. During sleep, the body:

• Slows your metabolism, heartbeat and breathing rate, which helps the body repair and replenish after daily physical activity.
• Triggers the release of hormones that aid the growth of bones, tissues and new red blood cells.
• Strengthens your immune and nervous systems.

Sleep Disorders

Although scientists don’t understand everything about the importance of sleep, adequate sleep clearly influences how you feel when you’re awake. A sleep disorder can make it difficult to deal with school, work and relationships when awake.

Many adolescents have a common sleep disorder called delayed sleep phase syndrome. This disorder, caused by puberty-related changes in the body’s internal clock, means you turn into a night owl just at the time your family wants to go to sleep. It also means you want to sleep later in the morning. This pattern is hard to change, so you may end up sleep-deprived because school starts before you’ve gotten the needed eight to ten hours of sleep.

More serious sleep disorders include sleep apnea, in which breathing temporarily stops during sleep, or chronic insomnia, when you regularly have difficulty falling asleep. If you think you suffer from one of these disorders, please see your doctor.

Getting a Good Night's Sleep

Everyone has problems sleeping at times, especially during adolescence. Here are some tips to increase your chances of sleeping better:

• Eliminate caffeine from your diet, including foods that have caffeine, such as chocolate.
• Set a regular sleep schedule and stick with it, even on weekends.
• Avoid exercise after dinner.
• Wear comfortable clothes or pajamas to bed.
• Make sure your room is not too hot or too cold.
• Avoid TV, music, phone or computer time at least one hour before bed.
• Use meditation or relaxation techniques
• Try the old standby, counting sheep, or count backwards from 100 — in other words, an activity that’s repetitive and lacks stimulation.

If you’re still tired after trying these suggestions and your lack of sleep is hurting your daily school work or relationships, please see your doctor.

Last Reviewed: July 2019