Why Do Humans Need To Sleep?

            There are many theories behind the reasons why we need so much sleep. The evolutionary theory states, that the inactivity at night is an adaptation that serves as a survival function, by keeping us out of harm’s way at time when we would be particularly vulnerable. This behavioral theory has evolved to become what we now recognize as sleep. There are factors that can influence sleep patterns such as your physical size, muscle mass, and brain size. While you are sleeping, an anabolic process or building process restores the body’s energy supply that has been depleted throughout the day; also the body starts to repair itself and the muscle tissue is rebuilt and restored.

At times, we do not get nearly enough sleep that our body needs. Sleep deprivation can affect our personality, our sense of humor, we become irritable, and are less tolerant of the world around us. A lack of sleep can also affect our cognitive process. Without the proper amount of sleep and rest, our over worked neurons can no longer function to coordinate information properly. Fifty-six studies were reviewed at the Department of Neurology in Erfurt, Germany, that explored cognitive dysfunctions in people with sleep-related breathing disorders (SRBD), insomnia, or narcolepsy. Individual study outcomes were grouped according to neuropsychological functions. Consistent evidence was found for impaired driving simulation performance in SRBD patients. Other neuropsychological functions with less obvious impairment included attention span, divided attention and sustained attention for SRBD patients;  attention span, verbal immediate memory and vigilance for insomniac patients, and  sustained attention, vigilance and driving simulation performance for narcoleptic patients.

There are a lot of ways to improve our sleeping habits such as avoiding caffeine, alcohol (which may bring on sleep, but after a few hours alcohol acts as a stimulant), and avoid smoking too close to bedtime. Always make your bedroom is a quiet, dark, and cool environment, and try to keep a constant sleep schedule. You should also lighten up on evening meals, balance your fluid intake later in the afternoon, and exercise earlier in the day, if possible. There are a few ways to seek treatment for sleep deprivation such as, going to a sleep specialist, who are trained to evaluate individuals for sleep disorders, and taking melatonin, which is a receptor agonist, that has been found effective for short term treatment of insomnia. When we are able to receive eight to nine hours of sleep a night, we are more alert, energetic, and are happier.

http://healthysleep.med.harvard.edu/healthy/matters

Fulda S., Schulz H. (2001) Cognitive dysfunction in sleep disorders. Sleep Medicine Reviews, 5(6), 423-445