It is very important for one to understand their sleeping cycle in order to have good night's sleep
. Our sleeping pattern is aligned with our internal body clock that is affected by a number of factors including time of the day, light and other factors affecting sleeping and waking up.
At night your go through various stages of sleep, moving back and forth from deep sleep to more alert stages.
Sleeping Cycle can be divided into two broad categories i.e. REM sleep and Non REM sleep. In the REM sleep, one experiences fast movement of eyeballs to and fro, hence giving it its name. This sleep is characterized by irregular and fast breathing that is not too deep. The body may also find it hard to keep its temperature in check during this period as the heart rate might increase causing high blood pressure. The limbs may also become temporarily paralyzed during REM sleep. However the most significant feature of this period is active dreaming. A person awoken from REM sleep can effectively recall what he was dreaming about.
Non REM sleep is based on 4 stages of deep sleep varying in their level of alertness. Stage 1 comprises of light sleep when the brain waves start slowing down, muscles start relaxing with the eye movement slows down. It's easier for a person to be awoken during this time before. In stage 2, 3 and 4 the level of brain activity and the shooting of brain waves progressively slows down. The brain waves in stage 3 are called delta waves that are mixed with higher frequency waves. Stage 4 comprises mostly of delta waves.
Stage 3 and 4 are known as Deep Sleep in which there is no eye movement or muscle activity. It is very hard to wake a person up from deep sleep.