The importance of sleep to the body has not been adequately established by scientific research; however we can deduce the importance of sleep by the fact that when a person is well rested and able to sleep well are more alert, active, concentration is at its peak and in sum healthier than those who have not slept well. Moreover, scientists have found that during sleep, the body is able to regenerate and renew itself by the repair and growth of body tissues. During sleep, we spend less energy than being awake, and it seems that this is when the body is able to heal itself.
Our body has a reserved amount of energy that it uses as fuel during the day, this reserve is used up when we are active and awake, however when we are asleep, this reserve is again filled by the body to prepare for the next day. Thus, when a person is not able to sleep, he/she feels tired, sluggish and fatigued. Sleep is also necessary for growth (Myers, 2004); studies have shown that the growth hormone is activated during sleep as well as the development of bones in infants and young children.
Which is why, babies and young children need more sleep than adults. It has also been said that it is during sleep that the brain encodes the information it has received to memory (Myers, 2004) as suggested by the intense activity of the brain during sleep which is why those who lack sleep are often forgetful and has shorter attention span.
Reference Myers, D. (2004). Exploring Psychology 6th ed. New York: Worth Publishers.