Sleep Paralysis — Causes, Symptoms, Treatment, and Prevention | Sleep Clinic Services

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Sleep Paralysis — Causes, Symptoms, Treatment, and Prevention

sleep paralysis

Imagine waking up in the middle of the night unable to move or speak. You see a dark shadow standing in your room and you feel like someone is holding you down on your bed. You might feel a strange sensation like electricity running through your body. It seems so real, the next morning you still feel terrified. It sounds like a scene from a horror movie but it’s a relatively common waking nightmare known as sleep paralysis.

Episodes of sleep paralysis generally last for less than a couple of minutes. It feels like being unconscious but you can’t move and it happens either while you’re falling asleep or waking up.

As you’re falling asleep your body relaxes and usually, you’re so relaxed that you become unaware of any changes to your body. But if you suffer from sleep paralysis your mind may still be slightly active and you’ll notice that you can’t move or speak.

Alternatively, during the REM cycle of sleep, your muscles turn off. If you become aware towards the end of your REM cycle you may notice that you can’t move.

While you may have never heard of sleep paralysis, it’s actually a relatively common condition. In their paper Prevalence of Sleep Paralysis, Brian Sharpless and Jacques Barber combined more than 30 studies on sleep paralysis giving them a huge sample size of over 36,000 people. They found that 8% of people experience sleep paralysis. And in high-risk groups (people with disrupted sleep patterns) as many as 28% of people suffer from sleep paralysis.

What Causes Sleep Paralysis?

While sleep paralysis is extremely terrifying it is more often than not completely harmless.

The main cause of sleep paralysis is sleep deprivation, specifically caused by:

-       Sleep apnea and snoring,

-       Changing sleep schedules,

-       Certain medications,

-       Anxiety and stress disorders,

-       Alcohol, nicotine and drugs, and

-       Narcolepsy and nighttime leg cramps are also common triggers.


There is also a high occurrence of sleep paralysis in teenagers.

What Are the Symptoms of Sleep Paralysis?

Sleep Paralysis — Causes, Symptoms, Treatment, and Prevention

When waking or falling asleep you will experience a minute or two of being unable to move or speak. Some people have also reported feeling a weight on them or a mild choking feeling and hallucinations.

In fact, it’s because of these symptoms that in the past it was thought that sleep paralysis was caused by demons holding people down.

But the hallucinations commonly experienced are simply because your brain is still in a state of dreaming.

If you’ve experienced sleep paralysis before you may find that the hallucination you had was almost exactly the same as other people’s hallucinations. As supernatural as this may sound, there is a logical explanation.

Research conducted by Cheyne, Rueffer and Newby-Clark published in Consciousness and Cognition journal found that there are 3 types of sleep paralysis hallucinations:

1. The Intruder

Commonly explained as a dark shadowy figure or a presence in the room. The intruder is caused by the hypervigilant state initiated in your midbrain.

2. Incubus

Described as pressure on the chest, difficulty breathing and pain. Incubus is caused by the effects of hyperpolarization of motoneurons on perceptions of respiration. For example, when you realise you can’t slow your breathing as a result of REM stage immobilisation of your muscles, you may feel muscular resistance – particularly on your chest.  

3. Unusual Bodily Experiences

Sufferers experience a feeling of floating/flying, out-of-body experiences, and feelings of bliss. That’s because when you’re awake, different parts of your brain allow for head and eye movements. The part of your brain that coordinates these movements is also closely tied to centres in your brainstem responsible for regulating your sleep-wake cycle.

This part of the brain connects your body with the external world. Neural firings that stimulate certain parts of the brain often result in different perceived ‘unusual bodily experiences’ during sleep. These hallucinations start because of conflicting information about your body position and motion.  

Cheyne, Rueffer and Newby-Clark also found that sleep paralysis novices experienced The Intruder and those who had suffered sleep paralysis for a long time experienced bodily hallucinations. So, if you experience sleep paralysis for the first time, the reason it’s so terrifying is that you are seeing or sensing a dangerous intruder in your room.

Understanding the way your brain works may help to calm you during a sleep paralysis episode.

What is the Treatment For Sleep Paralysis?

Sleep Paralysis — Causes, Symptoms, Treatment, and Prevention

Sleep paralysis can be terrifying if you’ve never experienced it before.

It’s important to stay calm and realise that it will pass in a minute or two. Try to regulate your breathing and focus on wriggling a finger or toe.

If you can remind yourself that the hallucination you’re experiencing is a normal brain reaction it can help.

There is no treatment for sleep paralysis. Prevention is the key.

How To Prevent Sleep Paralysis?

To prevent sleep paralysis you need to improve your sleep hygiene. Here are our tips for preventing sleep paralysis:

  • Have a warm bath before bed to help you relax,

  • Cut down on screen time at night and don’t use screens for an hour before bedtime,

  • Don’t drink alcohol or eat a heavy meal before bed. While both may help you fall asleep, they will disrupt your sleep cycle,

  • Try sleeping on your side, not on your back,

  • Reduce or eliminate caffeine in your diet. Caffeine affects sleep and can contribute to anxiety,

  • Stick to your sleep schedule. Try to be consistent with the time you go to bed and wake up in the morning.


Many doctors say that sleep paralysis is simply a sign that your body is transitioning through sleep cycles and that it’s nothing to worry about. However, if your sleep paralysis episodes are happening more frequently or you are worried about them, it’s important to see your doctor to check if there is another underlying problem.

  • Sharpless, B. A., Barber, J. P., Lifetime prevalence rates of sleep paralysis: A systematic review. Sleep Medicine Reviews, Volume 15, Issue 5, October 2011, pp 311-315.
  • Cheyne, A., Ruefferlan, R. Newby-Clark, R., Hypnagogic and Hypnopompic Hallucinations during Sleep Paralysis: Neurological and Cultural Construction of the Night-Mare, Consciousness and Cognition, Volume 8, Issue 3, September 1999, pp 319-337.