Bizarre Awakenings

Recently, I've been experiencing a problem with odd adrenaline jolts (unknown sensation of fear) and muscle spasms awakening me. As far as I can remember, I'm not dreaming when this happens, so it's apparently not from nightmares. I also suddenly get this sort of thing happening when I'm not even quite asleep (or at least not deeply enough to know it), but trying to fall asleep. This isn't something which has typically been normal for me, but has become regular over the past month or so.



I don't think it's apnea... although the jolt of adrenaline does stop my breathing for a second when it happens. It's sort of something that worries me, since my stepfather essentially died due to apnea five years ago or so (but why I'm slightly fixated on it now, I have no clue). The thing is though, I don't sleep on my back (always on my side) and don't generally snore, which are common tendencies for people with apnea.



It also is not due to any noise or sensation that I can recognize. Also note that I don't get this sort of sudden unexplained adrenaline jolt outside of the context of trying to sleep.



Any ideas of what the heck could be going on here? It's freaking me out a bit -- not enough to visit an actual doctor about it, but it's sort of weird.