REM: What is the REM sleep stage and why it is important

REM stands for Rapid Eye Movement. This is the sleep cycle when your brain is most active. During REM sleep, your brain will process information, store memories and dream.

When does REM sleep occur?

REM sleep occurs several times during the night. The first episode of REM sleep usually occurs about 90 minutes after you fall asleep. Each episode of REM lasts between 10 and 60 minutes and they get longer as the night goes on.

The stages of sleep are as follows:

Stage 1: This is the lightest stage of sleep. If you are woken up during this stage, you may feel as though you haven’t slept at all. During this stage, you may experience sudden muscle contractions and hallucinations. Your eyes will move slowly under your eyelids and your brain waves will slow down, but they are still mixed with those of a wakeful state. This stage lasts for about 5-10 minutes.

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Stage 2: This is a deeper stage of sleep than Stage 1. Your heart rate slows down, your body temperature drops and your eye movements stop. You spend about half of your total sleeping time in this stage. Brain waves slow further and become more regular. If you are woken up during this stage, you may feel groggy and disoriented for a few minutes. This stage lasts for about 20 minutes.

Stage 3: This is the deepest stage of non-REM sleep and it is also called slow-wave or delta sleep. Your heart rate slows down even more and your breathing becomes slower and deeper. Your muscles relax even more than in Stage 2 and it becomes difficult to wake you up during this stage (although some people can be awakened easily). If you are woken up during this stage, you may feel disoriented for a few minutes. This stage lasts for about 30 minutes.

Stage 4: This is the deepest stage of all and it is also called delta sleep or slow-wave sleep (SWS). Your heart rate slows down even more and your breathing becomes slower and deeper than in Stage 3. Your muscles relax even more than in Stage 3 and it becomes very difficult to wake you up during this stage (although some people can be awakened easily). If you are woken up during this stage, you may feel disoriented for a few minutes. This stage lasts for about 30 minutes.

What happens if I don’t get enough sleep?

If you don’t get enough sleep, you may experience any of the following symptoms:

Feeling tired during the day (even if you got enough hours of sleep)
Feeling irritable or cranky
Falling asleep at inappropriate times
Feeling depressed
Having difficulty concentrating
Having difficulty remembering things
Having trouble making decisions
Having trouble solving problems
Feeling anxious or worried
Feeling restless
Feeling sleepy or drowsy
Having trouble staying awake while sitting still, watching television or reading
Having trouble falling asleep at night
Waking up frequently during the night
Waking up too early in the morning
Having a hard time getting back to sleep after waking up in the middle of the night
Experiencing frequent nightmares
Experiencing vivid dreams having difficulty waking up in the morning
Experiencing physical symptoms such as headaches, stomachaches or muscle aches
Experiencing emotional symptoms such as feeling sad, angry or moody for no reason
Experiencing behavioral symptoms such as being unusually quiet or withdrawn
Being unable to enjoy normally enjoyable activities
Feeling unusually hungry or thirsty
Experiencing an increased appetite
Experiencing weight gain due to an increased appetite
Experiencing weight loss due to a decreased appetite
Experiencing changes in sexual desire or activity
Experiencing changes in menstrual cycles
Experiencing changes in bowel movements
Experiencing changes in urination habits (such as needing to urinate more often)
Experiencing changes in vision (such as blurred vision)
Experiencing changes in hearing (such as ringing in the ears)
Experiencing changes in sense of smell (such as being unable to smell certain odors)
Experiencing changes in sense of taste (such as being unable to taste certain foods)
Experiencing changes in coordination (such as being clumsy)
Experiencing changes in balance (such as being unable to walk straight)
Experiencing changes in memory (such as forgetting things that happened recently)
Experiencing changes in concentration (such as being unable to focus on one thing for very long)
Feeling unusually hot or cold
Feeling unusually sweaty or clammy
Feeling unusually dizzy or lightheaded
Feeling unusually weak or tired
Feeling unusually numb or tingly
Feeling unusually shaky or tremulous
Feeling unusually anxious or nervous
Having difficulty breathing normally
Having difficulty swallowing normally
Having difficulty speaking normally
Having difficulty moving normally
Having difficulty controlling bowel movements
Having difficulty controlling bladder function
Having difficulty controlling sexual function
Having difficulty controlling emotions (such as feeling unusually sad, angry or moody)
Having difficulty controlling thoughts (such as feeling unusually confused)
Having difficulty controlling behavior (such as being unusually withdrawn or quiet)