Sleep paralysis happens when, during waking up or falling asleep, a person is aware but unable to move or speak. One may hallucinate that means hear, feel, or see things that are not there. The condition can be triggered by fear, sleep deprivation, psychological stress, or abnormal sleep cycles. The underlying mechanism is believed to involve a dysfunction in rapid eye movement sleep (REM sleep). It generally last less than a couple of minutes and may occur as a single episode or be recurrent and also played a role in the creation of stories about alien abduction or other paranormal events.
It is recommended that people be reassured that the condition is common, generally not serious and may occur in those who are healthy, with narcolepsy (a long-term neurological disorder that involves a decreased ability to regulate sleep-wake cycles), or it may run in families as a result of specific genetic changes. Males and females are affected equally with 5% regular episode. Between 8% and 50% of people experience sleep paralysis at some time.
The central symptom of sleep paralysis is being unable to move during awakening. Imagined sounds such as voices, whispers, humming, hissing, static, zapping and buzzing noises are reported during sleep paralysis. People also have sensations of being dragged out of bed or of flying, numbness, and feelings of electric tingles or vibrations running through their body.
It may also include hallucinations, such as a supernatural creature suffocating or terrifying the individual, accompanied by a feeling of pressure on one's chest and difficulty breathing. Another example of a hallucination involves a menacing shadowy figure entering one's room or lurking outside one's window, while the subject is paralyzed.
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