ok, one more long post, I'm sure those who've been through it won't mind the read.
cut and paste:
Sleep paralysis is disorder that is both common and terrifying. There are two major types of sleep paralysis: common (typical) and hallucinatory (hypnagogic) sleep paralysis.
Common Sleep Paralysis
According to most researchers ( in a 1992 Gallup poll ) nearly every adult will have an episode of Common Sleep Paralysis (CSP) every couple of years. In the 1950ies and 60ies researchers discovered that sometimes sleepers gain counsciousness finding their bodies temporarily "frozen". This temporary paralysation affects the gross motor functions and macro muscle groups of the body. This state lasts between 15sec to a minute ( though subjects report that it lasts longer.)
These episodes of paralysis baffled sleepers and medicals professionals for centuries. It was not until R.E.M. and its correlation to the dream state was discovered that the mystery of Sleep paralysis started to unfold. Researchers soon discovered that hormones were released during the R.E.M./dream state that paralysed the body and kept it from acting out the contents of the dream. During most regular sleep cycles the hormones begin to wear off even before the dream is completed and thus people wake with a full funcitionning body. In rare occasions the hormones are still actively suppressing the gross motor functions of the body and thus upon waking the individual finds its body temporarily paralysed.
Though waking to this helpless state can be disturbing for the individual, it is perfectly harmless and fairly common. There are rare cases were some people produce too much of the hormone and will suffer from frequent sleep paralysis. There are other cases, where people do not produce the hormone at all.
Hallucinatory sleep paralysis
A more terrifying sister to the common sleep paralysis is the hallucinatory sleep paralysis also known as the hypnagogic sleep paralysis and the Hag phenomena.
There are three major differences between Hallucinatory Sleep Paralysis (HSP) and CSP.
Characteristics of sleep paralysis
1 Whereas CSP is common and universal HSP is rare and seems to be geographically episodic.
2 CSP is of raletively short duration where HSP can last as long as seven or eight minutes.
3 The major difference of course is that CSP maybe unsettling for the sleeper but the HSP is accompanied by a nightmarish hallucination.
There is evidence that HSP seems to affect an area (e.g. a village) much like an epidemic. A region that has had no HSPs reported may all of a sudden be innundated by sleepers suffering from HSP. Though this is relatively new research it seems regions stay infected for upwards to three years, with the most common being only a few months. There is of yet no explanation for this.
HSP also seems to run in families, but a hereditary connection is still to be found. A great deal of research is currently being conducted in Canada and Europe.
The most striking difference between HSP and CSP are the horrifying hallucinations that accompany the paralysis. The source of the hallucination has often been attributed to the hypnagogic state (the state between wakefulness and sleep.) An individual usually awakens either because they hear something or they feel something. The thing to remember is this occurs outside of a dream sequence/plot. The individual is wide awake yet paralysed like in CSP. Moments after the person is awoke they are startled by a terrifying visual hallucination. Almost inevitably, this hallucination takes on a stereotypical form. It is usually a vision of a small malevolent creature that straddles the victim. The creature then either compresses the chest or attemps to strangulate the victim. Most victims report that the creature is actively trying to kill them.
The visual hallucination has been variously interpreted throughout time and in different cultures as being: indigestion ("hippocrites" for the Hellenic Greeks), guilt for the Romans and the Egyptians, witchcraft for the Mexicans and Yoruba people, demons for Medieval Europe, djinn for the Arabs, vampires for Europeans, Hag for the Irish and Scottish, spectral foxes for the Japanese, cats for the Chinese, ancestral ghosts for South-East Asians, etc. Despite the various interpretations, the descriptions of the hallucinations are remarkably similar. There are hudreds of folk remedies to avoid HSP.** But the most common is to not sleep on your back. Almost all attacks have been reported by people sleeping on their backs.**
maybe ask my sister, she had that course only a few weeks ago.
)
but it is clear that one is caused by trauma, the other is just ‘normal’