Sleep is a natural recurring state of body and mind, often characterized by decreased awareness, a relatively reduced sensory activity, decreased muscle activity and mobility during deep sleep, and decreased interactions with the outside environment during light sleep. Sleep is a complex process which involves brain activities controlling the various programs and functions that control the body’s waking functions. It is also an important time to repair the damage done during the day to cells. The state of sleep is required for the re-growth and maintenance of cellular health and function, but the quality and amount of sleep are largely determined by the individual.
Sleep can be broadly classified into several types, including transient sleep, rapid eye movement sleep (REMS), deep sleep, and non-REM (NREM) sleep. Each type of sleep has different characteristics, including both frequency and duration. For example, while dreaming, a person may undergo substantial changes in the pattern of muscle activity, temperature, brain activity, as well as hormone levels. REM sleep is a state where a person experiences memory lapses or catapults. Transient sleep can be found during moments when the brain is inactive or unconscious, such as while sleeping or drowsy after alcohol or medication use.
There are many factors that determine the quality and duration of each sleep state. These include but are not limited to: the availability of certain hormones, such as growth hormone, at the brain synapse; the availability of oxygen and nutrients in the brain; and the structural make up of the brain, including its size and connections. However, regardless of the amount of sleep allowed, the duration of each individual sleep episode is generally the same. In addition, the number of awakenings per night and the amount of sleep needed to achieve each successive awakening, also have direct influences on the quality and duration of each episode. In essence, our brains are constantly working to recall information we’ve previously absorbed during the day, as well as to predict future events.
The amount of sleep needed to function normally has an impact on daily activities. For example, in order for an individual to complete a work project, they must allow their brains to recuperate from the previous day’s activities. Without enough sleep, the ability to think and complete projects is severely limited. Similarly, the ability to remember things accurately is severely hampered without enough sleep. In essence, a person’s entire life is affected by the quality and duration of their sleep.
Rapid eye movement (REM) is the primary mechanism for dreams may actually play a role in the quality and duration of sleep. Rapid eye movement sleep is also called rapid eye movement (REMS). REM sleep plays a vital role in the body’s circadian rhythms and enables the body to conserve energy and enable the development of healthy sleeping habits. A REMS sleep episode is different from a non-REMS sleep episode, and this distinction is important in determining the importance of quality sleep for our health.
Chronic lack of sleep can lead to many serious health problems and some diseases like cardiovascular disease and diabetes are exacerbated by too much sleep or lack of sleep. Lack of sleep also increases the risk of developing Alzheimer’s disease and it has been linked with depression, anxiety, weight gain and poor memory and concentration. In these cases, more sleep may not necessarily be the solution. For those suffering from chronic sleep deprivation, solutions like controlling the environment and ensuring adequate levels of exercise may prove to be much more desirable.