For most people there is a clear boundary between being awake and being asleep. We don’t always know when we cross it, but we can feel it coming on and there is a distinct difference in the type of experiences we have in the real world and those we experience in the dream world.

In some cases, however, the boundary between the conscious and unconscious state gets blurred with aspects of both states mingling freely. Sleep paralysis is one such case. We do not yet fully understand sleep paralysis, but recent research is finally beginning to pull back the curtain a bit. So let’s start our investigation into this troubling phenomenon at the beginning.

What is Sleep Paralysis?

Sleep paralysis is so named because a person loses muscle control for a brief period of time during the transition between the waking and sleeping states. The person is aware of this loss of control, called “atonia” (1), but is unable to do anything about it. To make matters worse, they often experience hallucinations that impose themselves on their awareness and create a kind of surreal stew that can be very distressing.

Sleep paralysis is categorized in clinical circles as a type of parasomnia (2). There are several kinds of parasomnia but they all involve unusual behavior during sleep. The hallucinations during sleep paralysis originate in dreams, so the condition is categorized as a type of REM-related parasomnia.

During normal REM sleep (3) we experience sleep paralysis as a matter of course. Researchers believe our subconscious orders this short-term paralysis as a way of preventing us from acting out our dreams and perhaps hurting ourselves. In the vast majority of people sleep paralysis ends right before they wake up. Because of that, they are never consciously aware of it.

In some people, however, sleep paralysis carries over into the waking state and is mixed with disturbing imagery, producing a kind of blended consciousness that can be very disorienting and disturbing.

What Does it Feel Like During Sleep Paralysis?

The overriding feeling is one of being conscious but being unable to move. This may happen as the person is falling asleep, or it may occur as they are in the process of waking up. 3 out of 4 people who experience sleep paralysis also experience hallucinations.

It would be reasonable to assume that these hallucinatory images are related in some way to a dream the person was having when they woke up. But strangely, most sleep paralysis-related hallucinations seem detached and distinct from typical dream imagery.

For most people suffering from sleep paralysis these hallucinations fall into 3 categories:

• Intruders – Many people report either seeing someone in the room with them or sensing someone lurking in the shadows.
• Suffocation – Other people report feeling that pressure is being applied to their chest, creating a sensation they are suffocating or being held down. It’s not unusual for this type of hallucination to accompany the intruder hallucination.
• Out of body hallucinations – Technically called “vestibular-motor hallucinations” the person feels like they are moving independent of, or being lifted out of, their body.

The feeling of being unable to move combined with one or more of the above hallucinations can create a surreal episode that is incredibly distressing and may leave a lingering sense of dread or dissociation that is hard to shake. It should be mentioned, however, that a small number of people experience pleasant hallucinations.

Sleep paralysis may last for a few seconds or it may go on for up to 20 minutes. The average length of a sleep paralysis episode is about 6 minutes (4). Most episodes resolve on their own, or a person may be brought back to full reality by someone else trying to wake them, either by talking to them or touching them.

How Many People Suffer From Sleep Paralysis?

Researchers who sifted through data from numerous studies concluded that 7.6% of people have experienced sleep paralysis at least once in their life (5). Interestingly, they found a much higher rate of the condition among students (28.3%). Exactly why is not known, but it may have to do with students, especially college students, suffering more frequent disruptions of their sleep.

Causes of Sleep Paralysis

Perhaps the most common cause of sleep paralysis is narcolepsy (6). However, it is hardly the only possible cause. Others include:

• General lack of sleep – People who experience insomnia more often than normal also tend to experience sleep paralysis more than others. This may include people who drink a lot of coffee, those who live in noisy environments, and people who travel between time zones a lot on business.
• Atypical work schedules such as night work – People who work the night shift, or who switch back and forth between day and night shifts are at risk of experiencing sleep paralysis.
• Sleeping on one’s back – There is compelling evidence that sleeping on one’s back can induce sleep paralysis (7). Researchers looked at instances of people sleeping in a variety of positions and discovered that people sleeping on their back experienced more episodes of sleep paralysis than those sleeping in all other positions combined.
• Certain mental health conditions including PTSD and bipolar disorder – People who suffer from panic disorder, anxiety, PTSD, bipolar disorder and other mental health conditions seem to be more susceptible to sleep paralysis than those who do not suffer those conditions.
• Alcohol and substance abuse – It is believed that substance abuse, including alcohol abuse, leads to a variety of sleep disorders (8). These sleep disorders can then make a person more susceptible to experiencing sleep paralysis.
• Mental and emotional stress – Stress can prevent a person from getting to sleep, or it may cause them to wake several times during the night and have trouble getting back to sleep. These stress-related sleep disruptions are now thought to be associated with an elevated risk of sleep paralysis (9).
• Existing sleep disorders – People with sleep apnea show some of the highest incidents of sleep paralysis. Likewise, people who experience night time leg cramps (10) also tend to have a higher than normal tendency to experience sleep paralysis. There also seems to be a slightly higher risk for sleep paralysis among those who have a family history of the condition. However, as of this writing, there is no definitive genetic link.
• Lucid dreaming – An online survey conducted in 2017 (11) suggests there may be a link between lucid dreaming and sleep paralysis. However, the fact that the study was not conducted using strict clinical protocols indicates more scientifically rigorous follow-up studies are needed to confirm this alleged link.

In some cases doctors and sleep specialists will be unable to pin down the cause of a person’s sleep paralysis. Those cases are often categorized as “isolated sleep paralysis”.

Sleep Paralysis-Related Hallucinations

Most people who experience sleep paralysis also experience hallucinations that do not seem to be associated with dreams. These hallucinations fall into 1 of 2 categories:

• Hypnagogic hallucinations which occur while the person is in the process of going to sleep or…
• Hypnopompic hallucinations which occur while the person is in the process of waking up.

While these hallucinations are associated with the REM stage of the sleep cycle they are not typical dream imagery. That is, whether hypnagogic or hypnopompic the hallucinations almost always take 1 of 3 forms: intruder hallucinations, suffocation hallucinations or out-of-body hallucinations. That is in contrast to dream imagery which may take on countless forms.

Intruder hallucinations sometimes have some real world foundation that they build off of. For instance, the mind may transform a jacket and hat on a clothes rack into a person standing there staring at you. Or red lights on a power bank may become the red eyes of a monster gazing at you in the dark.

Not Aliens, Hypnagogic or Hypnopompic Hallucinations

There are many people who believe they have been visited, or even abducted by aliens. Research suggests that a good many of these alleged alien abductions are instead incidents of hypnagogic or hypnopompic hallucinations (12). And indeed, many alien abduction tales contain classic characteristics of sleep paralysis-related hallucinations.

For instance, the “abduction” happens after the person falls asleep. The alien or aliens are seen lurking in the room. The person is unable to run, and feels as if they are being restrained. When seen in the context of sleep paralysis, such a tale makes perfect sense and has nothing whatever to do with actual aliens.

In addition, many people claim they’ve been laid on a table and subjected to an examination by their alleged alien abductors. This too makes sense in the context of hypnagogic or hypnopompic hallucinations since they are more likely to occur when a person falls asleep while laying on their back, as they would if they were on an examination table.

Sleep Paralysis and Narcolepsy

Narcolepsy is a vexing, incurable condition, believed to be related to autoimmune function, wherein a person is unable to maintain a stable waking state. They are often overcome by a sense of sleepiness that may either lead them to seek out a safe place to nap, or to fight through the sleepiness in a groggy, compromised state. Perhaps paradoxically, most people with narcolepsy have difficulty getting a full, restful night’s sleep.

One of the classic symptoms of narcolepsy is sleep paralysis and the hypnagogic or hypnopompic hallucinations that come with it. Hence a large percentage of people who experience sleep paralysis are narcoleptic. If you are experiencing episodes of sleep paralysis you should raise the subject with your doctor who may want to conduct diagnostic tests to see if you have narcolepsy.

Should You Be Worried if You Experience Sleep Paralysis?

A sizable portion of the population will experience sleep paralysis at some point in their life. In most, it will be an isolated incident that, while distressing, does not reoccur and goes down in their personal lore as one of those things they tell friends about from time to time.

However, as we noted earlier, researchers believe some 7.6% of people experience sleep paralysis on a disturbingly regular basis. If these episodes are accompanied by hallucinations it may cause the person to actually fear going to sleep. That, in turn, can lead to a cascade of health problems, including a worsening of the sleep paralysis phenomenon.

In addition, as we just saw in the previous section, regular incidents of sleep paralysis may indicate the presence of narcolepsy (13). Therefore, if you have experienced sleep paralysis on several occasions you should broach the subject with your doctor who can determine if you have narcolepsy.

Treatments for Sleep Paralysis

Before any treatment can be prescribed your doctor will need to have a better idea what might be causing your sleep paralysis.

Different underlying causes will call for different modes of treatment. For example, if it is determined that you suffer from narcolepsy you may be prescribed certain medications specifically intended to address that condition.

On the other hand, if it is determined that your sleep paralysis is the result of sleep apnea, your doctor may suggest you use a CPAP machine (14) to alleviate the condition and allow you to get the continuous, restful sleep you need.

Prescription medications and CPAP machines are two entirely different therapies which points to the need to have an accurate diagnosis of the underlying cause or causes before deciding on a treatment method.

The Importance of Good Sleep Hygiene

Another thing to keep in mind is that sleep paralysis may not be a result of any underlying physical condition, but may instead stem from lifestyle choices. For example, if a person engages in substance abuse or drink a lot of coffee these may disrupt their ability to get the sleep they need and lead to episodes of sleep paralysis. Sleep paralysis may also be a side effect of poor sleep hygiene (15).

Sleep hygiene doesn’t mean washing up or brushing your teeth in bed, it refers to the state of your bedroom and your habits surrounding sleep.

If your bedroom or the area where you sleep is not set up properly it can cause you to experience disrupted sleep, and that could eventually result in episodes of sleep paralysis.

Likewise, if you go to bed at a different time every night, or sleep for different lengths of time from night to night, that could also spawn incidents of sleep paralysis and accompanying hallucinations.

What Can a Person do to Minimize the Chances of Experiencing Sleep Paralysis?

The first thing is to educate yourself about sleep paralysis. That should help dispel any fears you have about your experiences, as well as any feelings you may have that you are somehow “weird” or that you are the only one experiencing these things.

Sleep paralysis is more common than most people think and happens to people from all walks of life. If your sleep paralysis is the result of narcolepsy, work with your doctor and a sleep professional on ways to mitigate your condition.

If, however, your sleep paralysis is being caused by lifestyle or sleep hygiene issues it may be fairly simple to obtain at least some relief from the condition. Here are a few tips that might help.

• • Set a sleep schedule and stick to it – If you want to minimize the risk of experiencing sleep paralysis one of the most important things to do is to establish a stable sleep routing. That means going to bed at the same time every night and waking at the same time every morning. And make sure you get 6-8 hours of sleep per night.
  • Avoid sleeping on your back – As we mentioned earlier, there is evidence to support the theory that sleeping on your back will increase your risk of sleep paralysis. So one simple way to reduce that risk is to sleep on your side. If you naturally tend to gravitate toward sleeping on your back, try putting a pillow behind you in order to stop that from happening.
  • Don’t drink coffee after dinner – A lot of people have difficulty getting or staying asleep because they hang out with their friends at a place like Starbucks in the evening and drink coffee. Or they take work home and put on a pot of coffee after dinner to get things done. If you want to sleep better it’s important to make after dinner hours caffeine-free.
  • Exercise regularly – Regular exercise will not only help you feel better during the day, it will help you sleep better at night. Exercise can also help you work off nervous energy and reduce stress. Just make sure you don’t exercise too close to bedtime.
  • Get help for conditions that could be disrupting your sleep – If there are situations in your life causing you a lot of stress and anxiety do your best to resolve them. If you suffer from anxiety disorders seek medical help to bring them under control. Dealing with underlying conditions can make it easier to get to sleep and stay asleep.
  • Look into medications you are taking – Some medications are known to create sleep issues. If you are currently taking any prescription medications talk to your doctor about any sleep-related side effects they may be having on you.
  • Avoid purposely inducing lucid dreams – The practice of trying to intentionally induce lucid dreams has gained in popularity in recent years. Many people see it as a way to explore alternative realities without taking drugs. But lucid dreaming and sleep paralysis often go hand in hand (16). So if your lucid dreaming efforts are producing nightmarish sleep paralysis events, consider giving up the lucid dreaming.

Remember: You’re Not Alone

Sleep paralysis affects a large percentage of the population at one time or another, with nearly 8% of all people (that would be more than half a billion people considering the current world population) experiencing sleep paralysis on a fairly regular basis. So, although your experience may seem scary and you may feel like no one else could understand what you’re going through, that’s not the case. You are very definitely not alone.

If you experience more than occasional bouts of sleep paralysis, with or without hallucinations, talk to your doctor. It may be a sign of narcolepsy, or it may be caused by something else that could be addressed by updating your sleep routine or other aspects of sleep hygiene.