Everybody sleeps. It is a necessary function in order to maintain proper health. However, the processes involved in sleep are far more complicated than many of us realize while we are dozing off every night. Rest is broken down into stages, or sleep cycles, each with their own unique physical characteristics that are measured by the type and amplitude of brain waves. The two main sleep cycles consist of rapid eye movement sleep (REM) and non-rapid eye movement sleep (NREM). From here, NREM is further broken down into four phases labeled N1-N4, and each of these sleep cycles play an important role in the level of sleep we achieve each night.
Non-Rapid Eye Movement (NREM)
N1 - this phase consists of the transitional period between wakefulness and early sleep when the brain moves from alpha waves to theta waves. This cycle is sometimes referred to as "drowsy" sleep, as you become less aware of your physical surroundings and lose some muscle tone as your body begins to relax. Sudden twitching and muscle jerking may accompany this phase.
N2 - characterized by EEG events known as "sleep spindles" and "k-complexes" in which the sleeping person experiences brain wave bursts as the brain essentially shuts down the motor reflexes to prepare for deep rest. We become completely unaware or our surroundings. Most adult sleep consists of N2 sleep.
N3 and N4 - also known as deep sleep or delta wave sleep, are the sleep cycles in which most parasomnias, such as night terrors, sleep walking, bedwetting, and other events occur.
Rapid Eye Movement (REM) - REM sleep accounts for up to 25% of total sleep in adults. Sleepers show similar brain activity as when they are awake, and this is why REM sleep is often associated with dreaming. Muscular atonia sets in, which is believed to be a self-preservation mechanism that prevents us from acting out our dreams. REM occurs several times a night, with other sleep cycles (usually N2 and N3) between.
Sleep disorders occur when one or more of these sleep cycles are disrupted. If you believe you may be suffering from sleeplessness, insomnia, or another sleep disorder, contact your health care provider. They will be able to help you identify the cause of your problems and aid in a treatment plan that works best for you.
Everybody sleeps. It is a necessary function in order to maintain proper health. However, the processes involved in sleep are far more complicated than many of us realize while we are dozing off every night. Rest is broken down into stages, or sleep cycles, each with their own unique physical characteristics that are measured by the type and amplitude of brain waves. The two main sleep cycles consist of rapid eye movement sleep (REM) and non-rapid eye movement sleep (NREM). From here, NREM is further broken down into four phases labeled N1-N4, and each of these sleep cycles play an important role in the level of sleep we achieve each night.
