Why we Sleep

The function of sleep is still a be a mystery, since no general agreement exists. Recent tests have been done on human subjects and lab rats that are starting to uncover the mystery of sleep. These new findings may help people with sleep disorders sleep better at night knowing there may be a possibility that they could lead normal lives.

Sleep deprivation:

Complete sleep deprivation can eventually lead to death
Tests with lab rats showed that they would lose weight even though they consumed a great amount of food—this was possibly from excessive heat loss.
They died 10-20 days later, which is faster than if they slept normally yet didn’t eat.
It still is not clear whether the brain damage caused by sleep deprivation or the sleep loss itself. However, being drowsy while driving or doing other daily activities can be fatal.
Long term use of sleeping pills may shorten a person’s life span rather than lengthen it.

The theory about metabolism:

The smaller an organism is, the higher their metabolic rate and brain temperature is.
Metabolism generates free radicals, which are extremely reactive chemicals that can damage and kill cells.
When a person is sleeping, their metabolic rate and brain temperature is decreased, which provides an opportunity to repair some of the damage done while a person is awake.
Enzymes may be used to do this repairing, and while sleeping, the enzymes themselves are replaced with newer ones.
Rats w/ sleep deprivation have brain cell damage, so non-REM sleep wards off metabolic harm.