‘’Sleep’s the only medicine that gives ease.’’
– Sophocles, Philoctetes
Sleep is a natural state of mind and body followed by Relaxation of mind and body and vice versa. During sleep, some of the activities are inhibited by our brain like activities of senses and activities of voluntary muscles. Usually, stages of sleep are named as Stage 1,2,3,4 and REM (rapid eye moment) sleep.
Stage 1: Stage 1 is light sleep i.e., awaken easily. In this stage muscles start to relax, blood pressure and heart beat start to reduce.
Stage 2: In this state, eye moments stop.
Stage 3: In this stage, brain waves become extremely slow (known as delta wave).
Stage 4: In this stage, the brain produces delta waves. This state is also known as DEEP SLEEP or DELTA SLEEP. In deep sleep, some people experience bedwetting, sleepwalking or terror sleep. During this stage, there is no eye moment or muscle activity.
Stage 5/ REM Sleep: In this stage, most dreams occur. We can remember all our dreams during REM SLEEP. During this stage heart rate and blood pressure increases, breathing becomes irregular, male develops erections.
Humans can suffer from a number of sleep disorders like Insomnia, Narcolepsy, Sleep Apnea, Sleepwalking, REM BEHAVIOR DISORDER, CIRCADIAN RHYTHM SLEEP DISORDERS etc.
Some PSYCHIC DISORDERS like Major Depression, Mania, Generalised Anxiety and Dysthymic Disorder are associated with Sleep disorders like Insomnia, Hypersomnia, Sleepwalking etc.