The brain generates two distinct types of sleep. One is slow-wave sleep known as deep sleep and other is sleep with rapid eye movement which is also known as dreaming sleep. Most of your dreaming occurs during rapid eye movement (REM) sleep. REM sleep occurs several times during night sleep.
REM sleep is important because it is the restorative part of our sleep cycle. Nobody knows where our minds travel when we are in sleep. However it is important to our brain functions and also to rejuvenate nerve cells. In simple, we can say that your brain and body stay active while you are sleeping. Your brain is a wonderful organ in which most of the dreams come at night.
The Dreaming Brain suggests that in sleep we can access a bank of knowledge. But For most people, dreaming is purely a "mental" activity. Dreams mostly occur in the mind while the body is at rest. People who suffer from REM sleep disorder, they physically move their limbs or even get up.
The first REM sleep period is usually the shortest, lasts 10-15 minutes, but by the end of the night, it can last from 40 to 60 minutes. With each cycle, the REM period increases longer. This is one of the common type of sleep disorders.
Insomnia is a sleep disorder that regularly affects millions of people worldwide. The people who suffer from insomnia find it difficult to fall asleep, stay asleep, or both of them.
The people who suffer from sleep-related breathing disorders that face difficulty in breathing during the sleep. This is the very common type of sleep disorder. Obstructive sleep apnea is the most common disorder among all.
People with sleep disorders with a circadian rhythm sleep-wake disorder cannot fall asleep and awaken at a time that is usually required for work and study, as well as for social needs.
A parasomnia is an unwanted physical movement or action during sleep. The term “parasomnia” refers to all the abnormal things that can happen to people while they sleep. Some examples are the sleep-related eating disorders, sleepwalking, nightmares, sleep paralysis, REM sleep behaviour disorder, and sleep aggression.