Isolated sleep paralysis is not considered dangerous. It typically lasts a few minutes or less (although in rare instances can last over an hour – gasp!). As far as I know, it is not related to Ehlers Danlos Syndrome (EDS), mast cell disease, or POTS.
Sleep paralysis is considered a parasomnia (something unwanted that occurs during sleep or during the sleep/wake transition). It often occurs in those with narcolepsy, so if you also suffer from the other kind of EDS – excessive daytime sleepiness – and you experience hallucinations either upon sleep onset or upon awakening, you should consult with a sleep specialist.
I have experienced all of the symptoms of narcolepsy except for cataplexy, so I am quite familiar with how frightening an episode of sleep paralysis can be. I eventually learned that when I get myself locked up into the dreaded sleep paralysis state, I am actually in REM (aka dream) sleep and can dream anything I want. As soon as I start lucid dreaming about something nice, I either drift back into total sleep and don’t notice the paralysis or I wake up with a smile on my face. It’s taken a long time to develop this skill, though.
MTD