sleep paralysis and terror: the complete overview to Causes, Effects, and Symptoms

Sleep Paralysis: The Complete Guide to Symptoms, Causes, and Treatment

Sleep paralysis is horrifying! Here's everything you need to know about it.

Sleep paralysis can be terrifying. In this post, we’ll discuss the symptoms, causes, and effects of sleep paralysis.

Sleep paralysis (SP) is a condition during sleep where you’re unable to move any muscle, although at the same time you feel the sensation of being choked, strained, or attacked.

It occurs when you have a terrifying dream in which you feel like being choked, chased, or attacked.

Other times, in the dream, you are unable to speak, move or even flee even if you wanted to.   

Studies show that between 2 and 60 percent of people experience sleep paralysis in their lifetime. And it exists in over 100 cultures.

Here are some of the questions we’ll help answer in this post:

  • What is sleep paralysis?
  • When does sleep paralysis occur?
  • How do you feel when you have sleep paralysis?
  • What are the causes of sleep paralysis?
  • What are the effects of sleep paralysis?
  • Is sleep paralysis bad?

Let’s dive in right away.

What is sleep paralysis?

Sleep paralysis is when at some point in your sleep, you’re unable to move any muscle although at the same time you feel the sensations of being choked, strained, or attacked.

sleep paralysis is present in over 100 cultures

It is a stressful condition during your sleep when you are incapable of moving your muscles.

It happens right at the onset of sleep or when you’re waking up.  

People who have sleep paralysis describe it as a dream state where they tend to act out their dream.

The problem is this dream is a nightmare. Often you want to flee, fight or scream, but you’re not able to move any of your limbs.

When you remember these dreams after waking up, they often involve life-threatening events or even events that compromise your physical integrity.

Once you wake up, you become highly aware and alert to your environment.


These dreams can occur frequently or be one-time episodes. 

What triggers sleep paralysis?

sleep paralysis - when does it occur

Sleep paralysis occurs at the rapid eye movement (REM) stage of sleep. Let me explain.

There are four main cycles or stages of sleep. The first three stages are what are known as non-REM sleep stages. 

The last stage is called the REM stage (more on these in a moment). 

At this stage, the brain is active (like they’re when we’re awake) and often your eye movements become faster, swinging in different directions. 

REM sleep is characterized by the following:

  • increased blood pressure
  • faster heart rate
  • rapid breathing

Here’s what happens:

Dreaming occurs when our bodies transition between REM sleep. When we dream, our body turns off the muscle movement capability. 

This mechanism is meant to protect us from injuring our bodies when we dream.

It’s why you can take a walk in your dream without bumping into your dresser in the bedroom.

It involves neuronal firing, especially in the pons, lateral geniculate nucleus, and occipital cortex.

In sleep paralysis, your body fails to send the signal to your muscles to turn on the movement capability for a few seconds or minutes. Or at least your muscles don’t get the memo.

What are the signs and symptoms of sleep paralysis?

Sleep paralysis symptoms

Several decades ago, different cultures read different meanings into sleep paralysis. 

For some cultures, it wasn’t just a bad dream; it was evil or even a demonic visitation. 

But more research is beginning to show that while the experience is terrifying, it is medically harmless.

Some of the symptoms of sleep paralysis include:

  • Paralyzed and unable to move any part of your body
  • Unable to speak or scream
  • Fearful and terrified
  • Feeling of helplessness
  • Distress

Once the dreamer suddenly regains movement of some part of their body, the episode ends. 

And this regaining of control often involves rolling off the bed or shouting which wakes up another person in or outside the room. 

Let’s look at these symptoms in detail.

1. You’ll feel paralyzed

One of the most common sleep paralysis symptoms is the inability to move.

This is mostly because your brain and body are unable to send any signals to your limbs.

You want to move, flee, and scream for help but your muscles don’t respond.

Humans are wired to flee or respond to fear. For many years our ancestors (think hunters and gatherers) bolted or fought back.

SP turns off all of these evolutionary tendencies. 

2. You’re unable to speak or scream

The terror of sleep paralysis is that the intuitive reaction of humans to fear tends to shut down. One of these reactions is screaming or yelling or shouting back.

This may leave you feeling incapable and often has the horrible feeling of near-death experience 

3. You are terrified and fearful

Recurring sleep terrors are marked by fear and terror. Not only is the terror from the vivid dream of harm coming your way. 

But also the terror is also combined with your body’s inability to move, which takes the fear to an extremely high level.

It’s one thing being chased, but another thing if you can’t run away.

4. You feel helpless

In most cases, you can regain control in the final seconds or minutes which wakes you up. But that feeling can be horrifying as well.

You tend to feel helpless once you wake up.

That feeling is worse knowing no one else can or in the future will be able to help you if you are under attack.

5. You’ll feel distressed

The emotional impact of a terrifying dream can sometimes be draining, and this tends to be one of the symptoms of sleep paralysis.

Part of this is because of the seeming lack of control — you know what is happening but you (or more precisely, your body) cannot do anything about it.

What are the causes of sleep paralysis?

sleep paralysis and terror causes

Researchers from Harvard Medical School teamed up with the University of London and University of Sheffield scientists.

They did a systematic review of variables associated with sleep paralysis and found some telling insights.

Let’s look at some of the common causes they found.

Let’s get started.

1. Substance use like alcohol and smoking

Scientific studies into the impact of substance use on sleep paralysis (SP) occurrence are not conclusive.

For example, two nationwide studies in China and Japan recruited over 10,000 and 90,000 participants.

The researchers found that those who self-reported drinking a drink with alcohol in the last month were more likely to experience SP.

But another study in the UK did not find that drinking alcohol predicted SP, besides symptoms of anxiety, depression, and poor sleep.

The same mixed results go for smoking. 

One study in the Sleep Medicine journal found that those who smoked at least one cigarette a day were more likely to experience SP.

Meanwhile, other studies are yet to find confirming results. This remains a surprise to many researchers, given the negative impact of caffeine on sleep.

Bottom line: If you are a regular smoker or drinker who constantly experiences sleep paralysis, it might help to cut out the substance use. 

2. Stress and trauma


Trauma and stress is one of the leading causes of sleep paralysis.

Studies have shown that stress and life trauma may be a trigger for a high prevalence of sleep paralysis (SP).

For example, Canadian researchers examined how childhood sexual abuse (CSA) impacts SP prevalence in adults.

The researchers enrolled over 200 participants and reported their findings in the Journal of Anxiety Disorders.

This study categorized the cases of abuse into three groups: confirmed, unconfirmed, or no history of CSA

The findings showed that SP frequency and intensity of intruder and incubus hallucinations were significantly greater in both CSA groups as compared to those who did not report sexual abuse.

Another study by Harvard University researchers found SP prevalence was significantly higher in people who had childhood sexual abuse.

For example for those in the group who repressed the memory of CSA, the occurrence of sleep paralysis was 44%.

And for those who recovered the CSA memory, they had a 43 percent occurrence rate.

Both groups had a much higher rate than the control group who reported not having experienced CSA (13%).

Bottom line: Stress and trauma, especially from childhood abuse may be a factor in frequent SP episodes.

3. Physical illness

Do you have chronic pain? Do you struggle with certain physical illnesses?

Studies show have linked these cause factors to higher frequencies of sleep paralysis.

Take for example a study done by researchers at the University of Wisconsin.

The findings showed that chronic pain complaints were associated with SP experiences.

But that’s not all.

General health problems including obesity show some telling results.

One study reported that higher BMI (Body Mass Index) was linked to both lifetime and recurrent episodes of fearful isolated SP.

Bottom line: General health problems including chronic pain and obesity have been linked with SP episodes.

4. Beliefs and personalities

For those who had certain beliefs, sleep paralysis was long considered punitive. Some even considered it an act of higher power.

But recent scientific studies are beginning to shed more light on how this posture of beliefs and personalities may influence SP occurrences.

For example, studies show that the rate at which people are engulfed in their mental fantasies has an impact on the frequency and intensity of hallucinations.

Also, a study in the Journal of Research in Personality report that the level of “imaginativeness” of a person can impact SP frequency and intensity. 

sleep terror- "imaginativeness" and beliefs are some triggers

“Imaginativenss” included scales like:

  • Absorption
  • Fantasy proneness,
  • Magical thinking,
  • Imagery vividness, 
  • Paranormal and mystic beliefs,
  • Unusual sensory experiences

Bottom line: Personality and what we believe can be a factor in SP experiences.

5. Psychiatric illness and disorders

Another cause of sleep paralysis is psychiatric illness.

Studies show a fairly robust relationship between psychiatric illness symptoms and sleep paralysis (SP).

Some of these symptoms include:

  • Post-traumatic stress disorder (PTSD)
  • Panic disorder
  • Panic attacks
  • Bipolar disorder 

In general, poor mental health is strongly linked to those who have PTSD. And these people are much more prone to experiencing recurrent fearful isolated SP. 

Also, other studies confirm PTSD is associated with both the frequency and intensity of SP episodes.

Bottom line: poor mental health may increase the odds of having recurring SP.

6. Sleep disorders 

Sleep disorders are a collective term that refers to conditions that disrupt, prevent, or affect our sleep.

According to one research, about 70 million people in the U.S. experience at least one form of sleep disorder. 

If you are having trouble sleeping, it could be a factor in SP occurrences.

In one landmark population-level study, researchers enrolled over 8,000 participants. 

The goal was to understand the prevalence and pathologic associations of SP among participants. 

The research showed that non-restorative sleep, a common symptom of insomnia, was associated with increased SP rates.

Another study observed increased sleep paralysis in obstructive sleep apnoea (OSA) patients compared to controls.

Bottom line: common symptoms of sleep disorders have been linked to higher rates of SP


What are the effects of sleep paralysis?

sleep paralysis  and sleep terror effects

The effects of sleep paralysis (SP) are external. Researchers identified three effects. Let’s look at them:

The first is intruder-related. It is characterized by a sensed presence, fear, and auditory and visual hallucinations.

This sense stems from a heightened state of alertness in the midbrain.

The second effect is strain-related. This is characterized by pressure or strain on the chest resulting in chest pains or difficulty breathing.

This is because of the decrease in respiratory muscle activity during REM sleep. It is a result of the inhibition of motor neurons.

People who tend to experience sleep paralysis (SP) sometimes have the vestibular–motor experience.

This is characterized by strange out of bodily experiences like flying or floating. 

Sleep paralysis treatment: How to avoid sleep paralysis

sleep paralysis and sleep terror treatment

Studies show that sleep paralysis (SP) is not clinically harmful. When it happens, you need to know you are safe.

A good way of avoiding SP is to first identify what is causing those issues.

Researchers from Harvard Medical School teamed up with the University of London scientists to better understand SP.

They did a systematic review of variables associated with SP.

The results reported the top causes of SP to include:

  • substance use
  • stress and trauma
  • physical illness 
  • sleep problems and disorders (both objective and subjective sleep quality)

1. Start cognitive-behavioral therapy (CBT)

CBT is an effective treatment for sleep paralysis.

Studies show that cognitive-behavioral therapy (CBT) can help decrease anxiety, improve stress tolerance, and sleep disorders.

CBT is a technique that helps to disrupt thoughts or ideas that lead to sleep paralysis. 

The idea is that at the core of any sleep disorder or SP is an underlying habit, belief, and thought pattern. 

And if we can identify those triggers, it’ll be possible to prevent those thoughts from firing in the first place.

Early research into how CBT can help with isolated SP is beginning to show some promise although more research is needed.

2. Avoid alcohol close to bedtime

sleep paralysis treatment: Avoid alcohol close to bedtime

There is a common notion that alcohol helps people to sleep faster. That may be partly true, but it also has detrimental side effects. 

Some of the negative impacts of alcohol at bedtime include:

But it’s not only sleeping quality that’s harmed.

Drinking alcohol close to bedtime can lead to isolated SP episodes. These episodes may mostly be driven by hallucinations.

Staying away from alcohol right before bedtime is a simple but effective treatment for sleep paralysis.

3. Adjust bedroom temperature

sleep terror treatment: Adjust bedroom temperature

Bedroom temperature is a critical piece of your sleep environment, and a simple treatment if you experience sleep paralysis often.

Higher temperatures keep you more awake. And lower temperatures make you feel more sleepy.

If you don’t have the right temperature, sweating and discomfort may accelerate some form of a sleep-related disorder, including SP.

Make sure to have a bedroom temperature between 60 and 67 degrees Fahrenheit.

4. Maintain a sleep and wake bedtime routine

sleep paralysis treatment: Maintain a sleep and wake bedtime routine to fight sleep terror

We are creatures of habit, and it’s a good thing when it comes to sleep. 

When you have a specific time for going to bed and waking up, you cue your circadian system in a really powerful way.

Your body’s internal clock becomes aware of when to sleep and when to wake up.


Not only does this set time help with sleep disorders, but it can also help you fight off sleep disorders including SP. 

Bottom line: Proper sleep hygiene can make a big difference. But If you keep experiencing SP regularly, talk to your doctor. 

A doctor may be able to recommend ways to deal with some of the causes.

This in turn can reduce the frequency of your SP experiences.

Keep in mind that some cultures claim to have found a solution to sleep paralysis, but there is no scientific or clinical research to support any of that.

For example, several decades ago, Greek physicians used special dieting and phlebotomy as a way to manage patients’ SP. There is no scientific proof this works.

Related: Good Sleeping Habits to Help You Sleep Better at Night

5. Improve sleep hygiene

Studies show that proper sleep hygiene can help treat cases of insomnia, parasomnias, and improve sleep paralysis symptoms and causes.

Sleep hygiene refers to the impact of our external surroundings and habits when it’s bedtime. 

From what you wear at bedtime to what you listen to while you sleep, every little action counts if you want better sleep.

This might seem like a little change but can be a powerful treatment for sleep paralysis.

Is sleep paralysis bad?

According to research, sleep paralysis doesn’t have any long-term effects.

But different cultures, religions, and societies around the world may have different interpretations.

In different cultures, sleep paralysis gets interpreted as:

  • Demonic visitations 
  • Spiritual attack
  • Moral deviance

There is no clinical evidence to support any of these.

Instead of vilifying people who experience sleep paralysis, a useful approach is helping them identify the causes.

Knowing the causes can help educate and help the people involved. If the causes are linked to mental or psychiatric conditions, they can also be treated.


Sleep paralysis is quite common than you think and there are several symptoms. Older people are less likely to have frequent episodes.

There are no long-term harmful effects of sleep paralysis.

In this post, we’ve discussed sleep paralysis causes, symptoms, and treatment.

The sudden shock or discomfort from an episode should not be attributed as a moral or religious consequence.

Instead, help people who experience them to understand the causes of sleep paralysis in detail. This can help identify the conditions that lead to it.