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Why do we Sleep?

By: Wendy Jacob - Updated: 20 Aug 2012 | comments*Discuss
Accidents Anxiety Automatic Sleep

Ask someone why they sleep and they are likely to reply: "Because I'm tired of course…" Ask them why they are tired and they may reply: "I haven't had enough sleep…"This shows the importance of the relationship between sleep and being awake.

So why do we sleep? Could we do without sleep allowing us to work longer without our health suffering?

Sleep is not a luxury that we can do without. Without sleep our bodies, minds and lives suffer. It is impossible to live without sleep.

There are a variety of reasons why we need to sleep:

  • Sleep is needed for the body to recuperate.
  • Sleep is needed for growth and development
  • Sleep affects metabolism
  • Sleep affects our ability to perform
  • Sleep influences our ability to learn and our memory
  • Sleep affects mood

Sleep and Growth

The body is not 'dormant' during sleep. New proteins are synthesised, muscles relax and our energy is renewed. Hormones, such as the growth hormone needed by children are produced at night. Other hormones, regulating hunger and affecting weight are also affected by sleep. The body appears to need sleep to bring balance back into the body and 'fine tune' some processes.

Sleepy and at Risk

Experiments in sleep deprivation have shown that there are changes in the brain and in behaviour which impact on our health, intellect and safety. Our ability to learn and remember is affected by lack of sleep.

Research shows that children's performance is affected after a poor nights sleep. Studies have shown that more errors are made with inadequate sleep and that driving while drowsy is a major contributing factor in road accidents.

Although we may not be aware of why we need to sleep, most of us have experienced the consequences of a poor nights sleep. Feeling tired we may become irritable and lose concentration and find it difficult to perform even familiar tasks. Our mood may be affected causing emotional disturbances, which may manifest as anger, tearfulness, anxiety or depression.

Longer term sleep deprivation may result in psychological problems such as depression.

Sleep and Education

Lack of sleep inhibits learning and memory and has serious implications for children and students. Research shows that children are less able to learn and perform after a poor nights sleep. In older children and students lack of sleep is a serious problem, often due to lifestyle factors, such as social demands and the growth of internet use. Increased sleep has been shown to improve performance and memory.


The need for sleep changes as children age. When a child reaches adolescence the need for sleep decreases and studies have shown that they perform better if they receive more early morning sleep and a later school start. Rigid timetables mean that the body, throughout life, is being asked to fit in with work and school demands and the automatic nature of sleep is challenged.

Left alone in a natural environment, it is suggested an adult would sleep during the night and then have a further rest during the afternoon. This would give us enough sleep to meet the needs of our body and brain and leave us feeling healthy and rested. Society creates demands, which interfere with this cycle of waking and sleeping.

Sleep is needed by all ages for good physical, mental and emotional health. Add to this the pleasure of a good nights sleep and there are plenty of reasons why we should spend more time under the duvet!

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