Sleep paralysis – signs, symptoms and causes

Sleep paralysis Signs and symptoms

You should know that sleep paralysis is referring to a feeling of being unable to move, either upon awakening or at the onset of sleep. The awareness and senses of individual are intact but they can feel as if there is a pressure on them or as if they are choking. The sleep paralysis can be accompanied by intense fear and hallucinations. The sleep paralysis is not life – threatening condition but it can cause anxiety. Sleep paralysis can happen alongside other sleep disorders, such as narcolepsy. There are some studies in which are said that sleep paralysis often starts during adolescence and it can become frequent during the 20s and 30s and it is not a serious risk [1]. The sleep paralysis is undesired event which is associated with sleep or pasasomnia. This condition happens upon awakening in the morning or just after falling asleep, which is in the time between waking and sleep. These episodes are often accompanied by hypnagogic experiences, which are sensory, auditory and visual hallucinations. They can happen during the transition between sleeping and waking. These episodes consequently fall into 1 of 3 categories:

  • Intruder: There is a sense of threatening presence in the room or there are sounds of shuffling footsteps, doorknobs opening or a shadow man.
  • Incubus: When the affected person is in this category, then the person has feelings of pressure on the chest, difficulty breathing with a sense of being strangled, smothered or sexually assaulted by a malevolent being. In this category, individuals believe that they are about to die.
  • Vestibular motor: There is a sense of flying, floating, falling, spinning, hovering over one’s body or another type of out – of – body experience.

This problem (sleep paralysis) and the experience of it have been documented for centuries. It is noticed that people from different cultures can have similar experiences. The sleep paralysis is brief and it is not life – threatening condition but the affected person can remember it as horrifying and haunting. Sleep deprivation, jet lag, stress and panic disorder can trigger sleep paralysis.


Sleep paralysis signs and symptoms

Here are the most common signs and symptoms of sleep paralysis:

  • Having headaches, muscle pains and paranoia
  • Sweating
  • Feeling as if death is approaching
  • Having difficulty breathing
  • Feeling pressure on the chest
  • Having hallucinations and sensations that cause fear being unable to speak during the episode
  • Being consciously awake
  • An inability to move the body when falling asleep or on walking, lasting for seconds or several minutes

There are everyday non – threatening sensations, sounds and other stimuli that the brain in normal conditions is ignoring. But when someone suffers from sleep paralysis then they become disproportionately significant.

Sleep paralysis Signs and symptoms

Sleep paralysis causes

When we are sleeping, our body relaxes and voluntary muscles do not move. This (not movement) will prevent people to injure themselves when they are dreaming. The sleep paralysis is involving a disruption or fragmentation of REM (rapid eye movement) sleep cycle. The body is alternative between REM (rapid eye movement) and NREM (non – rapid eye movement). 90 minutes is the time in which there is one REM – NREM cycle. Most of the time spent in sleeping is in non – rapid eye movement. When the body is in NREM, then it relaxes. When the body is in REM, then eyes move quickly but the body is relaxed and dreams are happening at this time. When someone suffers from sleep paralysis, then his body’s transition to or from REM sleep is out of synchronization with his brain. The consciousness of the affected person is awake but his body remains in the paralyzed sleep state. Those areas of your brain which are detecting the threats are in a heightened state and they are overly sensitive. Here are some factors which are linked to sleep paralysis:

  • A family history of sleep paralysis [2]
  • Sleeping on your back [3]
  • Irregular sleeping patterns, due to jet lag or shift work [4]
  • Narcolepsy [2,5]

Also the sleep paralysis can be a symptom of some medical problem such as anxiety disorders, hypertension, obstructive sleep apnea, migraines and clinical depression.


[1] American Academy of Sleep Medicine. Sleep paralysis – Overview & facts. Sleep Education. Retrieved from

[2] Olunu E, Kimo R, Onigbinde EO, et al. Sleep paralysis, a medical condition with a diverse cultural interpretation. International Journal of Applied and Basic Medical Research. 2018;8(3):137–42.

[3] Denis D, French CC, Gregory AM. A systematic review of variables associated with sleep paralysis. Sleep Medicine Reviews. 2018;38:141-57.

[4] Spear L. The sleep scientists embarking on jet lag studies. Sleep Review. 2018. Retrieved from

[5] Denis D. Relationships between sleep paralysis and sleep quality: current insights. Nature and Science of Sleep. 2018;10:355–67.


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