The actual reason behind the need for sleep in humans and mammals is still a mystery. Sleep is defined as a natural state of rest characterized by reduced body movement and decreased awareness of surroundings. Sleep can be differentiated from other sleeplike states like hibernation and coma because sleep can be interrupted by external stimulation. However, the reasons why humans need sleep are often more pragmatic than tangible. Reasons for sleep are to relieve physical and mental fatigue, avoid medical complications resulting from a lack of sleep and to protect animals from their predators.
             The cost of not sleeping is great failing which will bring adverse effects on one's mental health. The sleep debt that we incur is detrimental to our mind and society. Lack of sleep affects us in our alertness, ability to reason, our moods and judgment. Sleep debt is like a bank account where the more hours that are being deprived from us on a daily basis add up. The net effect of this sleep debt will affect us and the society we live in. If a person were to have just one hour less of sleep a day it will not affect him much the very next day. However, if this vicious cycle continues and by the end of the week the person is 6 hours in the red then he is putting himself and others at risk. This is evident in the number of accidents in all modes of transportation. 10% to 20% of them are attributed to fatigue a year in the United States. Most official estimates are lower because there is no litmus test to check the victims of these accidents were deprived of sleep. The official estimate suggests that there are at least 100,000 accidents, 71,000 injuries and probably 1,500 fatalities every year in the United States due to people falling asleep at the wheel. The actual number maybe significantly more. Coincidently, in a poll done by the National Sleep Foundation in America found that 51% of drivers said that they had driven while drowsy and another 1...