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July 05, 2022

Sleep paralysis

Sleep paralysis

You know you are awake. You can identify the environment around you and move your eyes. You can breathe normally, even though you may be having a feeling of suffocation. But you can’t move, like you are paralyzed. It has a name: sleep paralysis.

This temporary ‘blocking’ of movement happens to everyone every night. It prevents you from kicking your bedmate if you dream that you are Neymar, for example.

But, for some people, it happens when they have just fallen asleep or just woken up. In this case, we have an episode of sleep paralysis.

What is sleep paralysis

Sleep paralysis is a phenomenon in which the regaining of consciousness occurs at the same time as muscle atony. Atony is a kind of temporary muscle ‘paralysis’ that happens during REM sleep and prevents us from having sudden movements while dreaming. In the case of paralysis, it happens out of REM sleep, which is unconventional. 

In other words, the person is fully aware of what is happening, but is unable to move, which creates a feeling of fear and fright, as they are unable to use any part of their body for a few moments.

In addition, sleep paralysis is often accompanied by hallucinations of a dangerous intruder in the room or a ghostly character, with chest tightness a vain attempt to flee. All of this only increases the fear that the phenomenon causes.

Sleep paralysis is a sleep disorder of the parasomnia type, which are unusual events or experiences during sleep, representing a middle ground between being awake and falling asleep. It poses no real danger of any kind.


According to the International Classification of Sleep Disorders, one in two people will experience at least one episode of sleep paralysis in their lifetime. Longer-lasting cases, called recurrent, can be experienced by almost 8% of the population.

The phenomenon is slightly more common in men and has a higher prevalence in non-white population groups. 

In general, symptoms of this sleep disorder begin to appear in childhood, adolescence, or early adulthood (up to age 25). The episodes start to be more frequent as the years go by.

What causes sleep paralysis

The diagnosis of a psychiatric illness is considered a risk factor for sleep paralysis, as well as anxiety, alcohol consumption, trauma, and family history.

Irregular sleep habits, sleep deprivation and other parasomnias also indicate a predisposition to develop recurrent episodes. Isolated episodes tend to happen during shift work or sudden time zone changes (jet lag).

Obstructive sleep apnea also has an important connection to the phenomenon. In one study, 38% of people with isolated episodes of paralysis were diagnosed with the disorder.

The exact cause of sleep paralysis, however, is still unknown, which has led sleep medicine to understand that the disorder is the meeting of several factors.

Diagnosis of sleep paralysis

In general terms, sleep paralysis diagnosis is simple, since the episodes have a characteristic of their own: movement impossibility with awareness of what is happening around.

Polysomnography recordings of episodes of the phenomenon showed muscle tone suppression associated with an EEG pattern of awakening and the presence of eye movement and blinking similar to that of an awake person.

Find the diagnostic criteria for the episodes below:

  • Report of impossibility of moving the arms or legs as soon as they fall asleep or as soon as they wake up.
  • Reports are associated with hallucinations or dream-like situations.
  • The polysomnography detects muscle strength suppression, a REM period of sleep latency, or dissociated REM sleep. 
  • Symptoms are not associated with other diseases or disorders. 


Firstly, the most important thing is to understand that sleep paralysis does not pose a risk to your physical health. But the fear that an episode creates can be a potential trigger for an anxiety crisis, in addition to the possibility of disrupting sleep quality, which consequently also increases the risk of a new episode.

The fear caused by the phenomenon cannot and should not be overlooked, but you are not at risk because of it.

Isolated episodes of this disorder do not usually require treatment, but recurrent episodes deserve special medical attention so that associated conditions, such as narcolepsy, insomnia, apnea or even those related to mental health are found and treated. 

Controlling these other disturbances may be the answer to reducing the occurrence of the phenomenon. 

Sleep hygiene is also an important mechanism in controlling paralysis, as it improves sleep quality, which, when low, is a trigger for the phenomenon. 

If you have recurrent (not necessarily frequent) episodes of sleep paralysis, see your doctor or sleep specialist. They are the ones who will be able to come up with the best treatment plan for your case.


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