Sleep Quiz: Sleep Hygiene & Sleep Facts

Sleep seems to be necessary to ensure proper functioning of the nervous system. Inadequate sleep can lead to numerous problems such as drowsiness, poor concentration, memory problems, and worsened physical performance. Prolonged lack of sleep can cause hallucinations and mood changes. Some experts feel that neurons (cells of the nervous system) become depleted of energy or filled with byproducts of cellular activity and that sleep allows them to repair themselves. Sleep might also offer an opportunity to exercise connections within the nervous system.

Newborns require a great deal of sleep. They sleep from 10.5 to 18 hours per day, with intermittent periods of 1-3 hours spent awake. Newborns may be active during sleep, smiling, suckling, seeming restless, or moving their arms and legs.

The sleep cycle progresses through stages 1-4, and another stage known as REM (rapid eye movement) sleep. The cycle repeats itself after REM sleep has passed. Almost half our sleep is spent in stage 2, with about 20% in REM sleep and 30% in all the other stages combined. Infants spend about 50% of their sleep time in REM sleep.

Sleep deprivation or lack of sleep is associated with a number of health problems, injury, poor quality of life, and mental illnesses. Lost work productivity and increased health-care costs are two other consequences of sleep deprivation. Obesity and depression are thought to be worsened by sleep deprivation.

Sleep disorders are very common in people with mental disorders, occurring in almost all patients with depression, schizophrenia, stroke, Alzheimer's disease, and head injuries. Lack of sleep can trigger seizures in those with some types of epilepsy. Prolonged or extreme sleep deprivation can cause hallucinations or paranoia in people who are otherwise healthy.

Many diseases, including infections such as the flu, tend to make us sleepy. This is probably due to chemicals called cytokines released by the immune system, which tend to promote sleepiness. This may have evolved because sleep may help the body conserve energy needed by the immune system to combat an infection.

The term "circadian rhythm" refers to changes in physiology, behavior, or mental processes that follow an approximate 24-hour cycle. Circadian rhythms are thought to be related to the light and darkness in the external environment; it is believed light can affect expression of genes that control body processes. These rhythms can influence the sleep cycle and other body functions. Abnormalities in circadian rhythms are thought to be related to health problems such as depression, obesity, diabetes, and sleep disorders.

Sleep hygiene is the sum of practices that promote regular, restful sleep. Components of sleep hygiene can include going to bed and rising at regular hours every day, making the bedroom relaxing and inviting, using the bed only for sleeping, and removing personal electronic devices and TVs from the bedroom.

Insomnia is experiencing insufficient or poor-quality sleep. It may involve difficulty falling asleep at night, staying asleep, or early morning wakening. Symptoms can include excessive sleepiness during the day and impairment in daily function. There are a number of causes of insomnia, including medical and emotional disorders, medication side effects, or sleep disorders. While worry may exacerbate insomnia, it is not a primary cause of insomnia.

It is a myth that the need for sleep decreases as we age. Our need for sleep actually remains fairly constant throughout adult life. Older adults may experience changes in their sleep patterns including more difficulty falling asleep and difficulty staying asleep. Some older adults report feeling inadequate sleep and daytime tiredness.

Depression is the mental disorder most strongly linked to insomnia. Research has shown people affected by insomnia were five times more likely to develop depression than people without insomnia. The symptoms of depression and insomnia can combine to make both conditions more difficult. Treating depression can often help sleep problems, and the opposite is also true – treating insomnia can help improve the symptoms of depression.

Drowsiness can also cause impairment when it comes to driving. Feeling sleepy can slow reaction times, reduce awareness, and impair your judgment - all of which increase the odds of having an auto accident. Sleep deprivation occurs due to a number of causes, any of which can increase the risk of accidents.

Sleep apnea is the temporary interruption of breathing during sleep. Obstructive sleep apnea is a result of the muscles in the back of the throat failing to keep the airway open,. This is the most common type of sleep apnea. Central sleep apnea occurs when the brain does not properly control breathing during sleep. Both kinds of sleep apnea can lead to poor quality sleep and low oxygen levels.