Sleep Paralysis


Sleep paralysis is a state whereby one feels unable to move, talk, or open the eyes shortly before waking up, and, in some cases, before falling asleep. The individual is fully alert during this event but is involuntarily unable to move. The episode occurs for a short period and resolves on its own or with the help of external stimuli, such as being touched or talked to. Sleep paralysis induces helpless motionlessness and overwhelming fear. The condition is caused by an overlap in the sleep-wake cycle whereby sleep persists into the wakefulness state. It is often symptomatic of other health conditions, thus identifying and treating the underlying complications tends to resolve sleep paralysis. Isolated cases of sleep paralysis that are not caused by any health condition are also common and tend to resolve on their own without the need for medication.

Symptoms of sleep paralysis

Sleep paralysis is characterized by the inability to move one’s body when in a wakeful state. This condition occurs when one is beginning to wake up and is aware of their present state. They can, therefore, remember the event clearly after waking up fully. During the incident, the individual feels paralyzed and goes through unpleasant experiences including:

  • Chest pressure and pain
  • Difficulty in breathing
  • Limb spasms
  • Extreme anxiety

The condition lasts for a short while, often seconds or a few minutes, and resolves on its own, more so after the individual has struggled to break out of it. External stimuli, such as being touched or spoken to, also helps in resolving sleep paralysis. Some people have recurrent episodes of isolated sleep paralysis, which occur at least twice in six months. The disorder causes a lot of distress. Other than the paralysis symptoms, other major characteristics associated with sleep paralysis are:

1. Sleep hallucinations

Sleep paralysis is often associated with sleep hallucinations, which are imaginary sensations that appear real to an individual. The common sleep hallucinations experienced are visual, auditory, and tactile. These hallucinations are different from dreams because they occur in the transition between sleep and wakefulness. They, therefore, appear real to the person and cause fear and confusion. The person believes strongly that they have seen, heard or felt something leading to significant fear responses. For example, in a case of sleep paralysis associated with sleep hallucinations, an individual may report seeing an intruder in the room who may attempt to strangle them. Sleep hallucinations are, therefore, common in sleep paralysis.

2. Fear responses

Fear is a key feature in all sleep paralysis cases. The condition causes an individual to feel helpless in a threatening situation, which leads to panic reactions. The person gets an overwhelming sense of fear as they struggle intensely to fight the paralysis and free themselves. The fear intensifies when sleep paralysis is associated with dreadful sleep hallucinations. Fear responses do not diminish even after a person has experienced sleep paralysis several times and has a proper understanding of such episodes. Thus, one’s natural acute stress reactions will activate each time a sleep paralysis episode occurs regardless of an individual’s history with the disorder. Studies show that sleep paralysis activates the amygdaloid fear circuitry at a core level, thus causing significant fear responses even after multiple episodes.

Causes of sleep paralysis

Sleep paralysis can be symptomatic of medical conditions, such as depression, anxiety disorders, and sleep apnea. It also frequently occurs as an isolated condition. The causes of isolated sleep paralysis are not yet known, but several potential risk factors have been identified. They include:

1. Dissociation in REM sleep

Sleep paralysis occurs when an individual experiences the Rapid Eye Movement (REM) sleep and wakefulness at the same time. This is a unique state because, normally, REM and wakefulness states do not overlap. When asleep, people experience dreams, some of which would lead to harm if acted out. When the overlap occurs between REM and wakefulness states, the dream sequence continues into wakefulness and, therefore, there is a possibility of acting out the dreams.

To prevent the individual from reacting to perceptions in dreams, the brain causes the body to be immobile for a short while until the individual is fully awake. This immobility is caused by the pons and ventromedial medulla. These two parts of the brain trigger the suppression of the skeletal muscles. They cause the release of GABA and glycine, which are inhibitory neurotransmitters that impact the interneurons of the spinal cord. Sometimes, however, a dissociation occurs and the individual wakes up before the phase when paralysis of the muscles is over. This unique dissociation occurs in REM sleep resulting in sleep paralysis. Thus, the individual remains involuntarily and temporarily paralyzed because the muscles are still immobile, but the brain is alert.

2. Stress and trauma

People who have experienced threatening or traumatic life events tend to have a higher number of sleep paralysis cases. Past trauma is frequently used as a predictor of sleep paralysis during diagnosis because it has a high association with the condition. Post-traumatic stress disorder and panic disorder have also been identified in many sleep paralysis cases. Individuals who have high life stress scores have a higher likelihood of experiencing sleep paralysis as compared to those who have lower stress levels. Stress and severe trauma are, therefore, considered potential risk factors of sleep paralysis and are useful in its diagnosis.

3. Genetic influences

Studies have shown that sleep paralysis is commonly heritable and can run in a family for generations. A family history of sleep paralysis increases the possibility of an individual experiencing the condition. The genes associated with the circadian rhythm have also been found to play a role in sleep paralysis. When the PER2 gene undergoes variations, it increases the risk of experiencing sleep paralysis. The PER2 gene is an important member of the Period (PER) family of genes that ensure a regular sleep-wake cycle. The alteration in the genes affects the circadian rhythm, thus leading to sleep paralysis.

4. Anxiety disorders

Sleep paralysis is common in people who have anxiety disorders. The occurrence of the paralysis, in this case, is not associated with the use of antidepressants and is solely caused by the anxiety. The mechanism by which anxiety disorders cause sleep paralysis is not well understood. Studies, however, suggest that the sleep disturbances caused by anxiety disorders lead to irregular sleep habits, thus triggering sleep paralysis. In such cases, identifying and treating anxiety disorders helps reduce the occurrence of sleep paralysis.

5. Poor sleeping tendencies

Some studies have shown that an irregular sleeping routine can increase the risk of sleep paralysis. In Japan, for example, up to 40% of the people experience sleep paralysis due to light pollution and their active nightlife. Irregular sleep habits can be caused by many factors, including irregular work schedules, drug use, medical conditions, and environmental conditions. These factors reduce the sleep quality of an individual and cause sleep deprivation. Sleep paralysis can then be triggered due to sleep deprivation. Narcolepsy, which is a sleep disorder that causes excessive day time sleepiness, is often associated with sleep paralysis. Having a proper sleep routine reduces sleep disturbances and increases the sleep quality of an individual.


Sleep paralysis requires medical diagnosis when it becomes recurrent or affects one’s lifestyle and sleep patterns. Severe sleep paralysis can cause an individual to fall asleep during unusual times or get anxious about going to sleep. The condition is diagnosed by using the information provided from the patient. The doctor will thoroughly review:

  • Possible traumatic experiences
  • Medical history
  • Family sleep disorder history
  • Sleep-wake habits
  • Present health conditions
  • Prescribed medications
  • Drug and alcohol use

In a positive diagnosis of sleep paralysis, doctors will confirm that the individual experiences involuntary immobility shortly before waking up fully. The patient will also be aware of the state they are in and struggle to break the paralysis. Significant fear responses will be observed as the person feels terrified and helpless during the event.

There are other health conditions that an individual might have that could also be useful in diagnosis. Conditions such as post-traumatic stress disorder, anxiety, narcolepsy, and high life stress levels can be indicators of sleep paralysis. Past trauma is frequently found to lead to sleep paralysis and is, therefore, used in the diagnosis.

Other than the patient’s medical history and the symptoms provided, the doctor can also use different tools to diagnose sleep paralysis, including:

1. Sleep diary

A sleep diary is a useful tool in the diagnosis of sleep disorders. The individual keeps records of their sleep and wake times for about two weeks. This information helps the doctor in assessing the patient’s sleep habits.

2. Polysomnogram (PSG)

It is a test that involves recording the brain waves, breathing, heartbeat, and limb movements of an individual when asleep. The sleep study shows the body’s activity and identifies any abnormalities.

3. Electromyogram (EMG)

An EMG is a test that measures the electrical activity in the muscles. During an episode of sleep paralysis, the level of muscle activity is greatly reduced. This state of low muscle activity is known as muscle atonia and it is seen to persist from the REM state into the wakefulness state.

4. Multiple sleep latency test

Sleep latency is the time taken by an individual to fall asleep. The multiple sleep latency test is used to determine how long it takes an individual to fall asleep. The results determine whether one’s sleep paralysis is associated with other sleep disorders, such as narcolepsy. People who experience recurrent sleep paralysis have short sleep latencies.


Most cases of sleep paralysis are not related to any serious medical conditions; thus, they resolve on their own and do not require any treatment. Recurrent sleep paralysis that causes anxiety and significant sleep disturbance, however, should be assessed by a doctor.

The treatment of sleep paralysis mainly involves treating the underlying conditions such as anxiety disorder, post-traumatic stress disorder, and narcolepsy. Some of the treatments that are recommended for sleep paralysis are:

1. Selective serotonin reuptake inhibitors (SSRIs)

Prescription drugs containing selective serotonin reuptake inhibitors (SSRIs) are commonly used to suppress anxiety disorders. They increase the serotonin levels in the brain by preventing the reuptake of the hormone. Sleep paralysis is commonly caused by anxiety disorders and, therefore, treating this condition stops the occurrence of the disorder.

2. A regular sleep routine

It is important to have regular sleeping times to prevent sleep deprivation. Insufficient sleep has been cited as a cause of sleep paralysis in many cases. One should practice good sleep hygiene practices by getting to bed on time, avoiding drugs and alcohol, avoiding stimulants before bed, keeping the sleeping area dark and quiet, getting enough sunlight during the day, and waking up at a fixed time. Good sleep hygiene improves a person’s sleep quality and reduces the occurrences sleep paralysis.

3. Cognitive-behavioral therapy

Cognitive-behavioral therapy is a common natural form of treatment that is used to help the individual understand their condition. When an individual does not understand the experiences that they are facing, they can get stressed. Stress aggravates the condition and can lead to more complications. Taking one through cognitive-behavioral therapy helps them to think positively. They can then deal with the condition using effective ways. Ultimately, the therapy will lead to a reduction in sleep paralysis episodes.

4. Care from friends and family

Some individuals who deal with sleep paralysis have experienced past trauma which causes anxiety and stress. Care and reassurance from friends and family are ( support systems), therefore, very important in helping them deal with the trauma. Sleep paralysis episodes may evoke the same feelings that one had during a traumatic incident. Thus, supportive friends and family can help in dealing with the panic by calming the individual down.


Sleep paralysis is a state of involuntary immobility that occurs when someone is asleep but alert simultaneously. It lasts for a short while as the person struggles intensely to free themselves. It eventually resolves on its own but causes significant panic responses in the individuals that experience it. The fear increases when sleep paralysis is associated with daunting sleep hallucinations. Sleep paralysis is caused by a dissociation in REM sleep that leads to the persistence of sleep in the wakefulness state. The diagnosis of sleep paralysis is based on the information provided by the individual. Tools such as a sleep diary, polysomnogram, electromyogram, and the multiple sleep latency test can be used to diagnose sleep paralysis and identify any other underlying health problems.

Several potential risk factors lead to sleep paralysis including trauma, stress, anxiety disorders, genetic influences, and sleep deprivation. These risk factors are analyzed and used in making a diagnosis involving sleep paralysis. In most cases, sleep paralysis occurs as a symptom of other underlying health conditions. These underlying conditions are, therefore, treated to alleviate sleep paralysis. Anxiety disorders, for example, are treated using selective serotonin reuptake inhibitors (SSRIs). When sleep paralysis occurs as an isolated phenomenon with no underlying health condition, it resolves on its own and often does not require any medication. Cognitive-behavioral therapy, regular sleep routine, getting adequate sleep, and care from friends and family can control sleep paralysis. An occurrence of sleep paralysis that causes stress and anxiety, however, should be analyzed by a doctor.



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