"In my opinion sleep is a habit acquired by the environment. Like all habits it is generally carried to extremes. The man that sleeps four hours soundly is better off than a dreamy sleeper of eight hours."
-Thomas Edison.
One of the most puzzling questions often asked is, "why do we need to sleep? The simplest answer is that our internal clocks are set to the 24hr sleep- wakefulness cycle. Sleep sets in when the body is tired.
Sleep is not unique to human beings. In fact all mammals and birds sleep mostly with their eyes closed. All mammals have their own requirement of sleep. As a general rule, the larger sized mammals sleep less than the smaller mammals. For example the giraffe and elephant sleep for only 2 to 4 hours a day, whereas bats and armadillos sleep usually for 18 hours a day. Most mammals adopt a certain sleeping posture; however, dolphins can sleep even when they are on the move.
Sleep has become a sub-specialty by itself and there has been extensive research on it in the last decade. We now know about the beneficial aspects of sleep on the human body and the mind. The healing powers of sleep make it an integral part of our survival and evolution. We should get adequate sleep in terms of quantity and quality to keep us functioning effectively. Lack of sufficient sleep is behind the host of sleep disorders. A basic awareness and knowledge of sleep disorders is essential to help us seek treatment at the earliest.