Updated: Oct 19, 2019
What type of adventures do we have when we sleep? Fun? Scary? Weird? Some, maybe not safe for the blog? We have come to associate REM (rapid eye movement) sleep with dreaming; with that, it has become the most popular stage - known to most of the population. In addition to the Rockstar, REM, we have 3 other stages of NREM (non-REM), that our brains line dance through the night.
N1 (non-REM stage 1), is a transitional stage. Light stage of sleep. As we drift into sleep, we are most likely in stage N1. Likewise, when we arouse and return to sleep, N1 will be the likely stage
N2 (non-REM stage 2), is the stage for which the majority of the night is comprised. During N2, our body temperature drops and we become unaware of our surroundings. Reduction in temperature allows the energy being made to aid in body repair, instead of heating (sleeping in a cool environment helps). It takes approximately 1200-1500 calories to heat the body. If our brains are awake, and not hopscotching through sleep stages, the body temperature will increase; causing the burning of calories and potentially hunger to increase calories. During this stage, we have a mechanism that tells the brain not to alarm or arouse due to noise or touch; sleep technicians and physicians will see a K-Complex waveform while reviewing brainwaves.
N3 (non-REM stage 3), is the deepest stage of sleep and most restorative. Our blood pressure drops, breathing slows, muscles relax, blood supply to muscles increases, tissue growth and repair occurs, energy is restored, and growth hormone is released. Thoughts and memories are consolidated. Very important stage for immunity boost and consistency. This is the stage we are hard to awake from. Remember that time we painted Chuck's face like a clown and put whipped cream in his hand? He was in N3 the whole time. Hilarious! One more thing about N3 is night terrors. Night terrors differ from nightmares. Night terrors feel extremely real, and we usually wake with racing heartbeat, sweating, and screaming.
REM occurs about 25% of the night. The first sign of it is usually 90 into sleep. As sleep goes on through the night, REM becomes progressively longer. The brain is active, making this a light stage of sleep. Our brains may drift between N1 and REM if we are tired during the day. During this stage, our brain eliminates harmful protein build-up (such as beta-amyloid; responsible for Alzheimer's disease) via cerebral spinal fluid. Memories and thoughts consolidated during N3 are transported for storage. Daytime cognition, clarity, and focus are associated with REM. The less consolidated REM we have, the more difficulties we have with focus and memory.
Thanks for reading! Better Sleep is a Better You!