Sleep: An interesting story

When you’re in a hurry to do your work, go to school, look after family, do you reduce your sleep time?  You might think that sleep is merely a “down time” when the brain shuts off and the body rests. It is not so. Sleep is essential for a person’s health and wellbeing, according to the National Sleep Foundation (NSF).

Sleep is as important as food and air. It is a necessary function required to support all human life, growth, development and brain function. Sleep keeps your mind alert and calm. It helps you in optimal daily functioning.

If you wake up tired after sleeping for eight hours or longer, more sleep is not what you need.  A better quality of sleep is what’s needed rather than more sleep.  Deep sleep is the most important type of sleep our body needs.

What is sleep?

Sleep was long considered just a block of time when you are not awake. But sleep studies done over the past several decades, have discovered that sleep has distinctive stages that cycle throughout the night. Your brain stays active throughout sleep, but different things happen during each stage. For instance, in one stage, you feel well rested and energetic the next day, and in another stage you learn or make memories.

During a normal night, people usually cycle through the various stages several times.

How much sleep is enough?

Sleep needs vary from person to person. These needs vary throughout the lifecycle. Most adults need 7-8 hours of sleep each night. Newborns sleep between 16 and 18 hours a day. Children in preschool sleep between 10 and 12 hours a day.

However, some individuals are able to function without sleepiness or drowsiness after as little as six hours of sleep. Others can’t perform at their peak unless they’ve slept ten hours. And, contrary to common myth, the need for sleep doesn’t decline with age but the ability to sleep for six to eight hours at one time may be reduced. (Van Dongen & Dinges, Principles & Practice of Sleep Medicine, 2000)

Some people believe that adults need less sleep as they get older. But there is no evidence to show that older people can get by with less sleep than younger people. Older people are also more easily awakened.

Research suggests that a lot of people can be reassured that six or seven hours sleep is okay. The acid test for enough sleep is whether you are sleepy or alert throughout the day. If you are alert, then your sleep is probably adequate.  But sleep is more important than you may think.  Insufficient sleep is associated with a number of chronic diseases and conditions, such as diabetes, cardiovascular diseases, obesity, and depression.

Why sleep is good for you?

Sleep deprivation affects us as well as others. Thousands of traffic accidents are attributed to sleepy drivers every year. The average night’s sleep in the UK now averages about 90 minutes less than it did in the 1920s, when it was nine hours a night.

Does it really matter if you get enough sleep? Yes. Both quantity & quality of sleep matter, but the quality of your sleep is important as well. In other words, how well rested you are and how well you function the next day depend on your total sleep time and how much of the various stages of sleep you get each night.

Performance: We need sleep to think clearly, react quickly, and create memories. In fact, the pathways in the brain that help us learn and remember are very active when we sleep. Studies show that people who are taught mentally challenging tasks do better after a good night’s sleep. Other research suggests that sleep is needed for creative problem solving.

Skimping on sleep has a price. Cutting back by even 1 hour can make it tough to focus the next day and can slow your response time. Studies also find that when you lack sleep, you are more likely to make bad decisions and take more risks. This can result in lower performance on the job or in school and a greater risk for a car crash.

Mood: Sleep also affects mood. Insufficient sleep can make you irritable and is linked to poor behavior and trouble with relationships, especially among children and teens.

Health: Sleep is also important for good health. Studies show that not getting enough sleep or getting poor quality sleep on a regular basis increases the risk of having high blood pressure, heart disease, and other medical conditions.

In addition, during sleep, your body produces valuable hormones. Deep sleep triggers more release of growth hormone, which fuels growth in children, and helps build muscle mass and repair cells and tissues in children and adults.

Another type of hormone that increases during sleep works to fight various infections. This might explain why a good night’s sleep helps keep you from getting sick and helps you recover when you do get sick.

The Different Stages of Sleep

Sleep consists of different stages.

Stage one: First ten-minute period of light sleep (drifting off from wakefulness) is stage 1. Stage Two is deeper and it lasts about 20 minutes. Stages Three and Four come after this, and are types of deep sleep.

Stage 1: Stage 1 is an initial period of sleep. It is also called as non- REM (REM – rapid eye movement) sleep. In this period you “drift off”.

Typical characteristics of Stage 1 NREM Sleep are:

Breathing becomes slow and even The heartbeat becomes regular Blood pressure falls Blood flow to the brain is reduced

Stage 2:  It is an intermediate stage of sleep. It lasts about twenty minutes. You gradually descend deeper into sleep, becoming more and more detached from the outside world. It is progressively more difficult to awaken you.

Stage 2 is characterized by:

Larger brain waves and occasional quick bursts of activity. You will not see anything even if the eyes are open. Bodily functions slow down. Blood pressure, metabolism, secretions, and cardiac activity decrease.

Stage 3: It is the beginning of deep sleep. It lasts for about thirty to forty five minutes after you first fall asleep.

Stage 3 is characterized by:

Brain waves are slow (at the rate of 0.5 to 4 per second) and quite large (five times the size of waves in Stage 2). These brain waves are known as delta waves. You are far more difficult to awaken as compared to stage 1 or 2 sleep. It takes a louder noise or an active attempt to wake you up.

Stage 4: The deepest sleep occurs in Stage 4.

Stage 4 is characterized by:

The brain waves (called delta brain waves) are quite large, making a slow, jagged pattern on the EEG. The sleeper experiences virtual oblivion. If the sleeper is a sleepwalker or a bed wetter, those activities will begin in this phase. Bodily functions continue to decline to the deepest possible state of physical rest. This first period of deep sleep is the deepest. The sleeper awakened from deep sleep will probably be groggy, confused, or disoriented. He or she may experience “sleep inertia” or “sleep drunkenness,” seeming unable to function normally for quite some time.

After the first phase of deep sleep ends, the sleeper returns to Stage 2 and then enters the REM state.

REM Sleep Stage

When you enter the REM stage, your brain suddenly becomes much more active.

Characteristics of REM State

Brain waves are small and irregular, with big bursts of eye activity. The brain wave activity at this time resembles waking more than it does sleeping.

The four NREM phases are characterized by progressive relaxation. But during REM phase, the body’s activity perks up considerably.

Blood pressure may increase drastically. Pulse rates increase in an irregular way The sleeper with cardiac problems faces the greatest risk of heart attack at this time. Breathing becomes irregular and oxygen consumption increases. The face, toes and fingers may twitch. A man experiences penile erections; a woman experiences clitoral engorgement. The sleepers’ large muscles are literally paralyzed. They cannot move their torsos, arms, or legs. The body seems to have abandoned its effort to regulate its temperature during the REM phase.

The first REM period is usually brief. After this, the sleeper may wake up briefly. This is quite normal. A good sleeper may not remember it the next day. A poor sleeper, however, may wake up at this point and have difficulty getting back to sleep.

Deep Sleep

Deep Sleep has been shown to relieve symptoms of insomnia, nervous tension, panic, anxiety and depression. Deep sleep is essential for replenishing our bodies and minds. During deep sleep the body heals itself by producing growth hormone that speeds the absorption of nutrients and amino acids to aid the healing of tissues.

Deep sleep is crucial for physical renewal, hormonal regulation, and growth. Deep sleep is the part of sleep that our body and brain needs to recover from the day. It’s sometimes called delta sleep, after the delta waves the brain generates. Deep sleep is our restorative sleep, during which our bodies repair themselves and are rejuvenated from the wear and tear of the day. Deep sleep is a lot more peaceful and restful.

Deep sleep is also a period of dramatically reduced blood flow and energy use for the brain, which is probably crucial for restoring energy that is used during the daily demands of self-conscious awareness (e.g., thinking). It is very hard to wake up from deep sleep because the brain has turned off its awareness of the external world. Deep sleep is the deepest of all the stages. Above all, physical regeneration occurs during this stage.

How to get a good night’s sleep?

A number of vital tasks carried out during sleep help maintain good health and enable people to function at their best. Not getting enough sleep can hurt memory performance, health, and your mood. Like eating well and being physically active, getting a good night’s sleep is vital to your well-being.

According to leading sleep researchers, there are techniques to combat common sleep problems:

Have a regular sleep/wake schedule Don’t drink or eat caffeine four to six hours before bed   Avoid alcohol and heavy meals before sleep Get regular exercise Minimize noise, light and excessive hot and cold temperatures where you sleep Develop a regular bed time and go to bed at the same time each night Try and wake up without an alarm clock Attempt to go to bed earlier every night for certain period; this will ensure that you’re getting enough sleep Relax before going to bed. Take time to unwind. Have some ritual before going to bed: Read, listen to music. See a doctor if you continue to have trouble sleeping. Your family doctor should be able to help you.

By: Pradeep Mahajan

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