Sleeping Well: What You Need to Know - Helpguide
Sleeping Well: What You Need to Know
Sleep Requirements, Needs, Cycles, and Stages

Why can't I sleep? Why am I so tired? If you're like half of all adults, you may not be sleeping well and not getting the right amount of sleep. Today's fast paced society can make sleep seem like a luxury, not a need, but this is simply not true: you need quality sleep for good health. Sleep deprivation affects your entire body and mind.

Getting good, restorative sleep is not just a matter of hitting the pillow at night and waking up in the morning. Regulated by your body clock, your nighttime journey consists of sleep cycles with specific sleep stages, all vital for your body. Understanding these sleeping needs, cycles and stages can help you get better sleep.

What happens if we don't get enough sleep?

Many of us want to sleep as little as possible. There is so much to do that sleep seems like a waste of time. Yet sleep, an essential time of rest and rejuvenation, benefits our minds and bodies in many ways. When you continuously don't get the amount of sleep you need, you begin to pay for it in daytime drowsiness, trouble concentrating, irritability, increased risk of falls and accidents, and lower productivity.

Sleep benefits to our mood, memory and concentration

Have you ever pulled an "all nighter" to study for a final exam, only to find that you can barely remember what you studied during the test? Sleep helps to organize memories, solidify learning, and improve concentration. Proper sleep, especially sleep where you are actively dreaming (REM sleep), regulates mood as well. Lack of sleep can make you irritable and cranky, affecting your emotions, social interaction, and decision making. Sleep deprivation also affects motor skills, enough to be similar to driving while drunk if seriously sleep deprived. Driver fatigue, according to the National Highway Traffic Safety Administration, causes over 100,000 accidents and 1500 deaths each year.

Sleep benefits to our immune system, nervous system and development

Immune system. It doesn't seem fair. Right when you are exhausted after a stressful move or a big project at work, you come down with a cold. That's no accident - sleep is essential to the immune system. Without adequate sleep, the immune system becomes weak, and the body becomes more vulnerable to infection and disease.

Nervous system. Sleep is also a time of rest and repair to neurons. Neurons are the freeways of the nervous system that carry out both voluntary commands, like moving your arm, and involuntary commands, like breathing and digestive processes.

Hormone release. Many hormones, substances produced to trigger or regulate particular body functions, are timed to release during sleep or right before sleep. Growth hormones, for example, are released during sleep, vital to growing children but also for restorative processes like muscle repair.
Sleep deprivation and how it affects your life

How do you know if you're getting the sleep you need? Sleep deprivation occurs when you are not sleeping the right amount for your individual needs. Sometimes sleep deprivation is short term, like a college student pulling an all nighter. Chronic sleep deprivation often occurs in professions who work long hours, caregivers with multiple responsibilities, a concurrent sleep disorder or another disease that interferes with sleep. If you are falling asleep as soon as your head hits the pillow, regularly need an alarm clock to wake up, or feel the need for frequent naps during the day, it is very likely you are sleep deprived.

Other signs you may be suffering from sleep deprivation include::
* difficulty waking up in the morning
* poor performance in school, on the job, or in sports
* increased clumsiness
* difficulty making decisions
* falling asleep during work or class
* feeling especially moody or irritated

Sleep deprivation can be dangerous not only to you but others, since it affects motor skills like driving. Chronic sleep deprivation is also thought to cause long term changes to the body, which contribute to increased risk for obesity, diabetes and heart disease.

Find out how much sleep you need

So how much sleep do you need? A rule of thumb is to consider how you normally feel after sleep. Do you feel refreshed and alert, or groggy and exhausted? If you don't feel refreshed, chances are you're not sleeping enough. Sleep requirements are highly individual and depend on many factors:
* your age and genetic makeup
* what you do during your waking hours, including exercise
* the quality of your sleep

[TABLE: Typical Sleep Needs]

Paying off your sleep debt

Your body can't just bounce back from not sleeping enough. Sleep deprivation adds up to what is called a sleep debt. A sleep debt can range from one night's very poor sleep to the accumulation of many days of not enough sleep. Although you won't be getting letters from creditors if you ignore this sleep debt, not paying it off leads to decreased mental and physical health.

Paying off your sleep debt and getting your body back to normal may seem difficult or impossible with work and family responsibilities. However, making up for lost sleep and improving future sleep habits will increase your productivity and health in the long run.

Short term sleep debt

For a short term sleep debt, like a night or two of little sleep, you may just need a day or two of increased sleep to make it up. However, try not to make it a habit. Making up sleep on the weekends so you can sleep less during the week, for example, can disrupt overall sleep quality. Your sleep will be better if you go to bed and wake up at roughly the same time each day.

Long term sleep debt

If you have been chronically sleep deprived, you might need a longer time to make up your sleep debt. You may even need to take a sleep vacation, where you devote a few days to sleeping as long as needed. Although it may seem excessive at first, soon your body will revert to your optimum sleep needs.

Sleep stages: the sleep cycle

Understanding sleep stages and the sleep cycle can help you get better sleep. Your sleep is regulated by an internal body clock, sensitive to light, time of day and other cues for sleep and awakening. When you fall asleep, your sleep goes in cycles throughout the night, moving back and forth between deep restorative sleep and more alert stages and dreaming. As the night progresses, you spend more time in dream sleep and lighter sleep.

There are two main types of sleep. REM (Rapid Eye Movement) sleep is when you do most active dreaming. Your eyes actually move back and forth during this stage, which is why it is called REM sleep. Non-REM (NREM) sleep consists of four stages of deeper and deeper sleep. Each sleep stage is important for overall quality sleep, but deep sleep and REM sleep are especially vital.

A typical night of sleep follows this pattern:

* Stage 1 (Drowsiness) - Stage 1 lasts just five or ten minutes. Eyes move slowly under the eyelids, muscle activity slows down, and you are easily awakened.
* Stage 2 (Light Sleep) - Eye movements stop, heart rate slows, and body temperature decreases.
* Stages 3 & 4 (Deep Sleep) - You're difficult to awaken, and if you are awakened, you do not adjust immediately and often feel groggy and disoriented for several minutes. Deep sleep allows the brain to go on a little vacation needed to restore the energy we expend during our waking hours. Blood flow decreases to the brain in this stage, and redirects itself towards the muscles, restoring physical energy. Research also shows that immune functions increase during deep sleep.
* REM sleep (Dream Sleep) - At about 70 to 90 minutes into your sleep cycle, you enter REM sleep. You usually have three to five REM episodes per night. This stage is associated with processing emotions, retaining memories and relieving stress. Breathing is rapid, irregular and shallow, the heart rate increases, blood pressure rises, males may have penile erections, and females may have clitoral enlargement.

Importance of deep sleep and REM sleep

Deep Sleep

Each stage of sleep offers benefits to the sleeper. However, deep sleep is perhaps the most vital stage. It is the first stage that the brain attempts to recover when sleep deprived, and the strongest effects of sleep deprivation are from inadequate deep sleep. What might disrupt deep sleep? If you are caring for someone around the clock, whether it is a small infant or an elderly relative with a serious illness, you might need to attend to them suddenly in the middle of the night. Loud noise outside or inside the home might wake you. If you work the night shift, sleeping during the day may be difficult, due to light and excess noise during the day. Substances like alcohol and nicotine also disrupt deep sleep.

Maximize your deep sleep. Make sure your sleep environment is as comfortable as possible and minimize outside noise. If you are being awakened as a caregiver, make sure that you get some time of uninterrupted sleep, especially if you have had some unusually disruptive nights. Don't be afraid to ask for help.

REM sleep

REM sleep, or dream sleep, is essential to our minds for processing and consolidating emotions, memories and stress. It is also thought to be vital to learning, stimulating the brain regions used in learning and developing new skills. Most of dreaming occurs during REM sleep, although it can happen during other sleep stages as well. There are different theories as to why you dream. Freud thought that dreams were the processing of unconscious desires. Today, researchers wonder if it may be the brain's way of processing random fragments of information received during the day. Much of dreaming is still a mystery. If REM sleep is disrupted one night, your body will go through more REM the next to catch up on this sleep stage.

Getting more REM sleep

Studies have shown that better REM sleep helps boost your mood during the day. How can you get more REM sleep? One simple way is to try to sleep a little more in the morning. As your sleep cycles through the night, it starts with longer periods of deep sleep. By the morning, the REM sleep stage is longer. Try sleeping an extra half hour to hour and see if your mood improves.

Improving your overall sleep will also increase your REM sleep. If your body is deprived of deep sleep, it will try to make that up first- at the expense of REM sleep.

Getting the sleep you need

How can you make sure you get the sleep you need? A few extra hours here and there if you are sleep deprived might make you feel better for a short time. But it won't get you the quality sleep you need for the best health. To consistently meet sleep requirements for both deep sleep and REM sleep, you need to set the stage for good sleep on a daily basis. This involves:
* improving your daytime habits
* creating a better sleep environment
* avoiding food and drink that might interfere with sleep
* developing a good bedtime routine

See Tips for Getting Better Sleep for how to design a routine and plan that works with your individual needs.

What if insomnia or another sleep problem is interfering with my sleep?

Do you spend hours staring at the wall at night, worrying more and more that you can't sleep? You are not alone - over 40 million Americans a year will suffer from some sort of sleep disorder. Common sleep disorders include insomnia, sleep apnea, restless legs syndrome, and narcolepsy. See the other articles in this series to learn more about causes and cures for common sleep problems

* Insomnia Causes and Cures - Relaxation Techniques, CBT and Other Drug-Free Treatments
* Sleep Disorders and Problems - Symptoms, Tests and Treatment
* Snoring - Symptoms, Causes, Cures and Treatment
* Sleep Apnea - Symptoms, Causes and Treatment
* Restless Legs Syndrome (RLS) - Finding Relief from Symptoms and Choosing a Treatment
* Narcolepsy - Symptoms, Diagnosis and Treatment
* Sleep & Aging - Healthy Habits to Reduce Sleeping Problems and Prevent Insomnia
* Sleep Medications - Benefits and Risks of Sleeping Pills and Sleep Medications

Related links for: Sleep Needs, Cycles, and Stages

General information on sleep

Why We Sleep - Reviews hypotheses on the function of REM and NREM sleep stages (Scientific American)

The Science of Sleep - Reviews the importance and universal need of sleeping, the sleep cycle, sleep stages and requirements (BBC)

Brain Basics: Understanding Sleep - An overview of the sleep process and its effects on the body, including sleep needs and benefits, dreaming, circadian rhythms, disease, and sleep disorders. (National Institute of Neurological Disorders and Stroke)

Why We Sleep - Some of the latest research on how sleep benefits brain function, including memory and learning (Time Magazine)

Sleep requirements and needs

How Much Sleep Do We Really Need? - Research on sleep needs and sample sleep requirements in different age ranges. (The National Sleep Foundation)

Pregnancy and Sleep: A Contradiction in Terms? - Explains sleep troubles in different pregnancy trimesters as well as sleep tips. (Swedish Medical Center)

Brain, Heal Thyself - What the brain does during sleep to repair metabolism, replenish energy stores and grow new neurons (American Psychological Association)

Let's Sleep On It - How sleep allows us to retain and consolidate new memories and skills (American Psychological Association)
Sleep cycles and stages

Stages of Sleep - Diagrams sleep stages and the sleep cycle. (
The effects of sleep deprivation

Sheep Dash! - A test of your reaction time. If you're sleep deprived, you will perform more poorly than usual. (BBC, UK)

Epworth Sleepiness Scale - Try this online test of sleep debt to tally your level of sleepiness. (University of Maryland Medical Center)
Sleep and children and teens

How Much Sleep Is Enough for My Child? - Tips on ensuring your child is getting adequate sleep; information on the sleep needs of different age groups. (

How Much Sleep Do I Need? - Provides tips on sleep requirements for teens and how to get it. (TeensHealth, Nemours Foundation)

Delving deeper into sleep and sleep problems

Information About Sleep - A comprehensive teacher's guide that describes sleep biology, sleep stages, common sleep misconceptions, sleep requirements, and sleep disorders. (National Institutes of Health; Sleep, Sleep Disorders, and Biological Rhythms)

Joanna Saisan MSW, Tina de Benedictis, Ph.D., Suzanne Barston, and Robert Segal, M.A., contributed to this article. Last modified: June 08.
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