Causes and tips for sleep paralysis

In sleep paralysis, we wake up from sleep but cannot move. We reveal causes and give tips against the uncanny phenomenon.

Have you ever dreamed that you can’t move anymore? This idea should be frightening for most of us. Something similar is experienced by people who are affected by so-called sleep paralysis. In this phenomenon, also known as sleep paralysis or waking seizure, we wake up from sleep and are conscious, but can only move our eyes and breathe. Arms and legs are as if paralyzed, and speech is also not possible. Sometimes the affected person manages to make isolated sounds such as a moan. Sleep paralysis usually lasts only a brief moment, but such an episode understandably provides a great shock.

Why does sleep paralysis occur?

In general, sleep paralysis belongs to the sleep disorders (“parasomnia”). Accordingly, the reason for the temporary paralysis is hidden in the different sleep phases that we go through several times each night. These sleep phases together form a so-called sleep cycle and proceed as follows:

Sleep onset phase: in the transition between sleeping and waking, the body relaxes, pulse and breathing become regular.

Light sleep phase: This phase is also known as stable sleep, breathing and heartbeat become calmer. We spend the most time in the light sleep phase – in fact, about half of the total sleep time.

Deep sleep phase: In deep sleep, the body begins to renew itself. Pulse and breathing are slow, cells begin to regenerate, and the brain processes all the events of the day. During the deep sleep phase, sleepwalking may also occur.

REM phase: In the REM (rapid eye movement) sleep phase, our brain is active – according to measurements, almost as much as when we are awake. The name originated because eye movements behind the eyelids occur during this phase in response to brain activity. The REM phase is also the dream phase – and the one in which sleep paralysis is most likely to occur. Medically, this variant of the phenomenon is known as hypnopomanic paralysis.

Why does sleep paralysis occur mainly during REM sleep?

During the REM phase, the skeletal muscles are as if paralyzed (“REM atonia”). What sounds scary at first, however, is actually a sensible protective mechanism. Because the inhibited muscles (“muscle atonia”) are intended to prevent us from executing movements from the dream in reality, if necessary, and thus perhaps injuring ourselves. When we wake up, this sleep paralysis is normally lifted – if this does not happen, we are in a state of sleep paralysis. However, it is also possible that sleep paralysis already occurs when we fall asleep. Medical experts refer to this as hypnagogic paralysis.

Since the eyes and the breathing reflex are not affected, we can look left and right and breathe normally despite the lack of muscle control. Usually only a few seconds pass before the sleep paralysis subsides, sometimes a few minutes. In rare cases, sleep paralysis lasts for up to an hour. Sleep paralysis often occurs in the supine position and more often causes accompanying symptoms such as hallucinations.

Is sleep paralysis dangerous?

That the experience of sleep paralysis can be unsettling is understandable. However, provided the waking seizure occurs infrequently, it is not dangerous. Those affected by sleep paralysis naturally perceive the condition as threatening and often feel that they are in respiratory distress. However, this is not the case – the respiratory muscles function completely normally even during sleep paralysis, and after waking up the phenomenon is often quickly forgotten, provided it does not occur repeatedly.

You should pay attention if you experience sleep paralysis more frequently. Because then each of these episodes could become a big burden on your everyday life. For example, it is possible that sleep paralysis could cause you to develop anxiety about going to bed. The paralysis could also be a symptom of another sleep disorder or even a mental illness. If you feel that there is more to your sleep paralysis than an occasional phenomenon, you should seek medical help. Your health care provider can advise you and refer you to a sleep lab for more specific treatment, for example.

Forms of sleep paralysis

Medically, there are four forms of sleep paralysis:

Isolated sleep paralysis: The isolated form of sleep paralysis occurs alone and is not a symptom of other possible disorders. Sometimes the phenomenon occurs only once, sometimes sporadically at monthly intervals. Usually, there are no sequelae such as anxiety, and affected individuals forget what they have experienced over time.
Anxious isolated sleep paralysis: In this form of sleep paralysis, accompanying symptoms such as hallucinations occur, which can cause lasting anxiety. For example, seeing apparitions or fearing that the sleep paralysis will now persist and that you will be trapped in your body forever.
Recurrent sleep paralysis: Those who suffer from sleep paralysis more frequently experience the recurrent form of the phenomenon. The paralysis may occur in phases on and off for several months.
Recurrent anxious sleep paralysis: The worst form of sleep paralysis for those affected is certainly the recurrent anxious variety. This is because it not only occurs at regular intervals, but additionally torments us with hallucinations, which in turn can cause great anxiety in the long term.

Typical symptoms of sleep paralysis

With sleep paralysis, various symptoms can occur that often make the frightening phenomenon even worse for sufferers than it already is. The most common symptoms of sleep paralysis include:

Hallucinations

In addition to physical paralysis, about one-third of all patients experience hallucinations during sleep paralysis. These are negative sensory illusions – those affected sometimes experience scenes like those from a horror movie and believe they are seeing monsters or death scenarios. Hallucinations cause the body to panic, which in turn leads to increased release of adrenaline and the affected person tries to fight the paralysis. However, it is not possible to regain control over one’s own body during sleep paralysis. As bad as the situation may be when one is in it: The nightmarish phenomenon subsides on its own after a short time, and then the hallucinations also subside.

The sensory delusions during nightmarish sleep paralysis can express themselves in many ways. Some people believe they hear sounds such as footsteps or screams during the waking episode, or suspect the presence of other people in the room even though they are alone. Shadows in the corners of the room suddenly become menacing dark figures or monsters, feelings of heat or cold may occur, and some sufferers also experience a feeling of pressure on the chest. Although breathing is normal during sleep paralysis, it may feel like suffocation. In some cases, patients also report out-of-body experiences.

Shortness of breath

In addition to the possible feeling of pressure on the chest, some people affected by sleep paralysis also have the feeling as if they cannot feel their breathing at all and thus suffer from shortness of breath. Medically, however, the feeling can be explained: Normal diaphragmatic breathing is maintained, but the so-called auxiliary breathing muscles, such as the abdominal muscles, remain without tension. This results in the sensed shortness of breath.

Catalepsy

The term catalepsy is used by physicians to describe short-term muscle failure. For example, the facial muscles may become slack, and in some cases the entire body is affected. This neurological disorder is more often associated with sleep paralysis.

Causes of sleep paralysis

So far, it is not entirely clear why sleep paralysis can occur. However, there are several factors that may make it more likely. These include:

Narcolepsy

So-called narcolepsy is also known as sleeping sickness and can trigger sleep paralysis. Affected individuals suffer from extreme daytime sleepiness and can suffer a sleep attack from one second to the next. The muscles go completely slack (cataplexy or muscle failure). The cataplexy can cause the patient to fall during a sleep attack and possibly cause serious injury. Unfortunately, there is no cure for narcolepsy at present, but various medications can be used to combat the daytime sleepiness that accompanies it.

Sleep apnea

The so-called sleep apnea (apnea = Greek for windlessness, also “sleep apnea syndrome”) can also trigger sleep paralysis. In sleep apnea, there are repetitive pauses in breathing during sleep, which can be very dangerous. Stopped breathing is always an alarm signal for the brain, which is why it increases the heart rate and blood pressure, among other things, as a reaction and activates the autonomic nervous system.

If left untreated, sleep apnea can trigger various secondary diseases, as Professor Ingo Fietze, head of the Interdisciplinary Sleep Medicine Center and a specialist in internal medicine, pulmonology and somnology at the Charité Hospital in Berlin, also confirms: “The breathing stoppages put a strain on the cardiovascular system, and the nocturnal oxygen drops on the brain. Long-term consequences include high blood pressure as well as cardiac arrhythmias, diabetes, dementia and other diseases.” The disease is most noticeable in the form of loud snoring and audibly labored breathing. Sleep apnea is treated individually, but often a breathing mask is used to prevent the breathing disorder. Patients usually receive instruction in the correct use of the mask in the sleep laboratory.

How can sleep paralysis be treated and prevented?

Since sleep paralysis cannot usually be prevented in every case, education is particularly important so that those affected can deal with it better in an emergency. The focus here is on informing people that sleep paralysis usually passes after a short time and that there is no danger from it. In particularly severe cases, medication can be used in consultation with a doctor, but there is no guarantee that this type of treatment will be successful. In acute cases, it can help to concentrate on one’s own breathing and to realize that sleep paralysis usually subsides quickly and that accompanying symptoms such as hallucinations also only occur for a short time.

Sufferers themselves can take a few steps to reduce the risk of sleep paralysis. The following tips can help:

1. proper sleep hygiene

To improve our sleep and prevent sleep paralysis, we can take some measures for better sleep hygiene. The right room temperature – for most this is between 16 and 18 degrees – is just as relevant for sleeping as a room that is as dark as possible and silence. Regular bedtimes are also important – so if you get up at seven in the morning during the week and go to bed at ten in the evening, you should ideally do the same on the weekend. This kind of routine generally helps with sleep disorders. Since the supine position seems to promote sleep paralysis, sleeping on your side or stomach is beneficial. If you have trouble falling asleep, you should tend to avoid naps – they may lengthen the time it takes to fall asleep in the evening.

It is often advised not to have a television in the bedroom because it emits blue light. This can upset our sleep-wake rhythm and cause the body to produce less of the melatonin known as the sleep hormone. For the expert Prof. Fietze, however, this is not the decisive factor: “If watching television helps you fall asleep, it is perfectly fine. And the effect of the TV away from the bed on melatonin is completely overestimated. Moreover, melatonin is not one of the strong sleep hormones.”

2. Reduce stress

Since stress is a big factor in sleep disorders and also sleep paralysis, sufferers should work to reduce it. Classic relaxation techniques such as yoga, meditation and autogenic training can help. Some patients also report success with hypnosis. Regular walks outdoors, especially in the countryside, also reduce stress, according to studies. The S3 guideline on the treatment of anxiety disorders also recommends exercise as a complementary measure for panic disorders.

3. rely on psychological help

Especially if you suffer from sleep paralysis more often and develop anxiety as a result, it is important to work on how you deal with it. A psychologist can help you with this. This is especially necessary if you become downright afraid of sleeping – because this not only increases the likelihood of sleep paralysis happening again, but can also have other serious health consequences.

But what helps when relaxation techniques and co. fail and you just lie wide awake in bed? “Get up, read, knit. Just do something relaxing. Sleep will come back on its own. Or watch a nature documentary or boring talk show that is as unexciting as possible,” advises sleep expert Prof. Fietze.