Different Stages Of Sleep Explained (Sleep Cycles, REM Sleep Etc)

A CRASH COURSE in the sleep stages.

What are the stages of sleep?

In terms of the actual sleep itself, what we know is that the brain undergoes several changes during the night. These form what are called ‘sleep stages’.

Each sleep CYCLE consists of 4 sleep STAGES. A sleep cycle lasts about 90 minutes, and every night we each have about 5-6 sleep cycles. Within each sleep cycle are these 4 stages, which cycle through in order.

Stage 1: Light Sleep (NREM)

You start off with light sleep during which you are still fairly alert and aware.

Any loud or soft noises will wake you and cause you to sit up. during this stage, the brain produces Beta waves, which are small and fast waves, typical of being awake or still alert.

How long can we go without sleep

If you’re woken up during this sleep stage, you often won’t actually remember being asleep, and will think that you were awake the whole time. People woken during this stage might say things like ‘I was just closing my eyes’ and not really remember being asleep.

It doesn’t matter too much if you’re woken up during this stage, an you won’t REALLY feel tired or frustrated (Unlike the later stages). This is a dreamless sleep stage (Usually. You CAN technically dream in NREM sleep but it’s much less common). NREM means NON REM or non rapid eye movement, meaning not many dreams.

Stage 2: More light sleep (NREM)

You then enter a short stage of sleep for about 10 minutes in which the brain produces Theta waves. These are very slow brain waves which CAN be used to lucid dream later.

If you’re woken during this stage, you might feel a little tired and annoyed. You’ll feel very tired and be ready to fall asleep again. This stage doesn’t last very long, and in some cases, lasts just a few minutes. It’s more of a transition stage moving you into DEEP sleep.

It’s also actually harder to be woken up during this stage. This is where you might start breathing deeper, and moving your eyes very slowly behind your eyelids. You might also snore in this stage.

Stage 3: Deep sleep (NREM)

After this, there is a stage of sleep called Stage 2 sleep. During this stage, the brain waves are short rapid bursts of rhythm called sleep spindles, and also during this stage, the body temperature decreases and heart rate begins to slow down.

This is the most important (debatable) stage of sleep, as it’s the most restorative. The body releases human growth hormone and repairs and injuries. It also recovers from exercise here, and repairs and grows/builds your muscles.

This stage of sleep is very important for a number of reasons, and it’s important to NOT interrupt this stage of sleep. If you’re woken during this stage, you’ll feel very tired, fatigued and annoyed. If you STAY awake a ... https://www.youtube.com/watch?v=AzB8mLBmUSI