What is Sleep?
Sleep is the regular period of rest in every 24 hours, when humans and other animals are unconscious and unaware of their own surroundings. As humans, we need different amounts of sleep depending upon our age – babies need many more hours than a healthy teenager for example.
Why do we need to sleep? Despite us spending a third of our lives asleep, doctors and researchers still do not know the actual purpose of sleep. But what they believe is:
- Sleep helps us repair the cells in our body
Whilst we are at rest and in a deep sleep our use of energy is much lower; this energy conservation seems to give us the opportunity to repair our bodies and recharge our batteries. - Sleep helps us conserve energy
When we are asleep our need for energy to live and interact with our environment reduces, compared with our needs when we are awake. - Sleep helps us form and retain our memories
Complex processes are involved in helping us to process and store sensory information into memories. Such sensory information is obtained from all of our senses, such as from what we see, hear, taste, touch or smell. - Sleep helps support our immune system
Poor sleep can make us more vulnerable to viruses which cause the common cold or influenza.
Overall, good quality and good quantity sleep leaves us refreshed and fully restored to function efficiently and remain wakeful the next day. In fact, studies have shown a direct link between the amount and quality of sleep and our abilities to function the next day. People with insomnia are more likely than people who can sleep well to have an accident or be less productive at work (due to absenteeism, reduced concentration or difficulty performing tasks).
Your sleep
Did you ever think about how much time you spend asleep?
An "average" person sleeps about 8 hours a day that is 56 hours every week, or 240 hours every month. In other words, an average person sleeps about 122 days a year, so a 75 year old person would have spent a total of about 25 years asleep.
We spend one third of our lives asleep, doing nothing. Is it true to say that sleeping is really doing nothing? During sleep we are unconscious and unaware of our surroundings but if we take a look at what is happening inside the brain, we will see that the brain is very active. Sleep is vital for survival and has an important role in various systems in the body. Poor or inadequate sleep can have serious consequences on overall health and wellbeing and in the long run it is associated with an increased morbidity. Unfortunately, sleep is sometimes given a low priority in modern life, according to the U.S National Sleep Foundation's, people in the US have worked more and slept less, over the last five years1.
Each year, 70 million people in the United States alone suffer from sleep disorders; the most common one is insomnia which manifests itself as transient or chronic sleep problems. These disorders account for an estimated $16 billion in medical costs alone in the U.S and about $100 billion each year in accidents, medical bills and lost work2.
