Why do i often get sleep paralysis?

I dont know why it happens but it is when you wake up but youre still in a semi sleep state...the things you see at this time are hypnogogic images...just like youre still seeing your dream. I used to get this a LOT, sometimes up to 4 times a night. I went to a homeopath and he gave me a remedy made from spider venom ( latrodectus, I think its called) and I havent had sleep paralysis in over a month.