REM state is the Rapid Eye Movement state of our sleep, when most of our dreaming occurs. About 20% of our total sleep time during the entire night is spent in REM state.
During REM state, our brain becomes active like when we are awake, while our body remains temporarily paralyzed.
REM Sleep Disorder occurs when this paralysis becomes incomplete or absent, causing us to enact our dream physically while asleep - this includes actions such as talking, punching, sitting and walking in sleep.
If these actions turn violent with the potential to hurt ourselves, or our partner, it is time to see a doctor.
The exact cause of this REM disorder is unknown (except in the event it shows up as a symptom of another, underlying disease), and hence is often misdiagnosed.
Other precautions to be taken can include - removing potentially dangerous objects out of bedroom, setting a cushion around the bed to prevent fall injuries, and having our partner nap on a separate bed.
Sleep paralysis is in a way the converse of the above REM disorder, where our brain fully wakes up, but the body paralysis continues. This causes us to become conscious, but unable to move.
Sleep paralysis is sometimes accompanied by hallucinations, and a sense of danger and fear.
However, we can take gratification in the fact that, by itself, the condition is quite harmless - unless it is associated with other conditions or diseases - and many people experience it, at least once or twice in their life time.
The whole episode typically lasts a few seconds to few minutes, and is often terminated by sound or touch.
While medical conditions like Narcolepsy are usually linked to the incidence of sleep paralysis - and may need medical intervention - there are also few other more common causes of sleep paralysis.
If you are experiencing occasional sleep paralysis because of lack of restful sleep, you can try listening to self hypnosis downloads right before bedtime every night, and that can help improve your sleep.
And in the event of frequent recurrence of sleep paralysis, like every week for several months, it is a good idea to consult a doctor.