Sleep & Rest

Sleep & Rest

Sleep is necessary for mammals and many other animals, in order to rejuvenate their bodies. During sleep consciousness is lost or reduced and we are less responsive to external activities. Most people need at least 8 hours of sleep per day in order to function at their highest level. Not getting enough sleep can increase the risks of cancer, heart disease, obesity and diabetes.

About Sleep & Rest

Sleep is a natural periodic state of rest for the mind and body, in which the eyes usually close and consciousness is completely or partially lost, so that there is a decrease in bodily movement and responsiveness to external stimuli. During sleep the brain in humans and other mammals undergoes a characteristic cycle of brain-wave activity that includes intervals of dreaming.

There are two stages of sleep, REM and NREM. NREM sleep is divided into 3 stages. At stage N1 the person is just beginning to fall asleep and may experience twitches. At stage N2 the brain experiences a burst of activity and muscular activity decreases. In N3 the brain slows and during this stage a person may experience night terrors or sleep walking. During REM sleep the eyes move rapidly and a person is most likely to dream.

How Much Sleep Do We Need?

The amount of sleep a person needs per night varies from person to person. The average amount of sleep needed for an adult is 7 to 8 hours per night. A study performed at the University of California concluded that the people who live the longest were the ones who slept 7 to 8 hours per day. Those who slept longer than that showed increased mortality.

Children need more sleep than adults. A newborn baby on average needs about 18 hours of sleep. A baby 1-12 months needs about 14 to 18 hours. A toddler aged 3-5 needs 12 to 15 hours and a preschool child needs about 11 to 13 hours. Children aged 5-12 need about 9-11 hours of sleep and Adolescents need about 9-10 hours.

What Happens If I Don't Get Enough Sleep?

Not getting enough sleep can increase the risks of cancer, heart disease and diabetes. Studies have also linked obesity to lack of sleep as well. Reduced amount of sleep can also affect cell renewal. Wounds may not heal as quickly as they would if they body was receiving an adequate amount of rest. Sleep deprivation also diminishes our mental functions as well as physical. Studies on children have shown that those children who had one hour less sleep than their peers did not perform as well on memory tests and attention than those who got more sleep. It is possible for a human to die from extended sleep deprivation, although there are no reported cases of it. In the 1980’s experimentation on sleep deprivation was performed on rats, which all died after 32 days without sleep.

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