From the alt.dreams FAQ, maintained by Olaf Titz (olaf@bigred.ka. sub.org):
"3.1. What causes sleep paralysis?
"A. Conventional wisdom: REM atonia is a normal function of the body. The muscles that move the body are "turned off" during REM sleep, which prevents you from acting out dreamed actions in reality. Non-REM sleep paralysis after waking up ("old hag") is caused by a failure to re-activate the muscles immediately. Normally this condition lasts only a few seconds, but sometimes it can go for a minute, which causes a very scary feeling. You are damn sure you're awake now but you can't move. This is extremely unpleasant but at least not dangerous."
Symptoms of old hag include hearing footsteps, seeing a presence (in the past, because of people's fear of "witches", this was often an old woman, from which the name derives), and a feeling of not being able to breathe or move.
Here is a typical Old Hag experience. This was posted on a.f.g-s.
From: bwallace@epix.net (Penny)
"... I turned out the light and settled down to go to sleep. As I was lying in bed thinking, I became aware of a rustling sound emanat- ing from the turret. I focused on the sound, trying to determine its origins. A breeze over papers? A mouse? As soon as I dismissed these possibilities the rustling sound stopped and was replaced by the sound of stealthy, shuffling footsteps that were headed in my direction. The sense of a presence was suddenly so strong that it filled the room. I was terrified. The critical detail here is that I clearly remember pulling the blanket over my head (I was lying on my back.) The next thing I knew I was paralyzed--I couldn't move a finger. The footsteps continued their approach and the next thing I knew, a tremendous weight settled on my chest, forcing me into the mattress. I felt that there was a menacing presence. [...] It was nasty! The intense, dreadful weight continued to press down on me, almost like a large animal settling itself on my body. I thought I would go through the mattress. I knew that I was awake, I was not dreaming, and that something evil was in the room with me. Somehow, my childhood years of Sunday School paid off and I prayed to be re- leased. In that instant, it was over."
Next time you read a book of true ghostly accounts, keep the old hag phenomenon in mind. Most likely you will find a few classic old hag experiences (especially by authors who are unaware of the phenomenon) which the victim assumed were paranormal.
FAQ EXTRA An amusing
anecdote involving sleep apnea sent in by a reader.
FAQ EXTRA An alternate
explanation of old hag involving astral projection or OOBE.
FAQ EXTRA More old hag stories from the true story archives.
This page (http://www.ghosts.org/faq/5-6.html) last updated April 13, 2005.