During REM sleep, people seldom dream.
There are 4 non-REM stages and REM sleep.
Sleep is prompted by natural cycles of activity in the brain and consists of two basic states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep, which consists of Stages 1 through 4. During sleep, the body cycles between non-REM and REM sleep. Typically, people begin the sleep cycle with a period of non-REM sleep followed by a very short period of REM sleep. Dreams generally occur in the REM stage of sleep. Then the cycle repeats all over again.
You will know when someone is in REM sleep when there eyes-lids are moving really fast back and forward. REM sleep is a sleep that is after your first 4 stages of sleep and is the stage of sleep that you dream.
Different stage of sleep. Dreams happen in REM sleep.
The longest REM cycle occurs in the early morning hours. This is why it's easier to lucid dream on weekends, longer hours of sleep in the morning.
There are 7: Distress Active Alert Alert Inactive Drowsiness Periodic sleep REM sleep Non-REM sleep
This usually occurs in REM sleep, when dream states occur. It is not necessarily pathological.
rem stand for rapid eye movement if you miss out on this sleep you become cranky and sometimes even see things that arent there it is the time in your sleep when you dream even if you don't remember it
In sleep apnea people enter REM sleep just fine. The problem is that when the muscles relax in the first part of REM sleep the airway collapses and they stop breathing. This interrupts the sleep cycle and they get poor sleep amongst other problems. Not entering REM sleep causes what is known as "REM sleep behavior disorder". They do not have the normal paralysis that accompanies the dream stages of REM sleep so they may act out dreams. Sleepwalking is one example. For more information see the link below.
REM or Rapid Eye Movement. You sleep in cycles, moving from lighter to deeper sleep and back. A sleep cycle lasts about 90 minutes, with REM occurring toward the end of each cycle. The REM stage gets a little longer in each cycle; you may only dream for a few seconds in the first sleep cycle, and for a large percentage of the last cycle of the night.
Truly "deep" sleep does not occur during REM sleep. REM sleep is when you are dreaming. It is deeper than light sleep, but not as far down in unconsciousness as "deep" sleep.