Thank you for your response, I have been under a lot of stress, always have. so the endorphins being released makes a lot of sense to me. and the getting back to sleep has gotten a lot easier. so thanks again
Everyone does it. I have. Guys release semen during nocternal orgasms, but since women don't have semen, the vagina just becomes lubricated. For guys, it's called "wet dreams". Orgasms occur during dream sleep, and you wake up right after it happens. Orgasms during sleep usually come from mental activity, rather than physical rubbing or stimulation. It has nothing to do with lack of stimulation. It's unknown what causes it...but there are some guesses. It could be your body had a rough day so it releases a little too many endorphains to relax, and it causes an orgasm...or pleasant dreams can cause a euphoric feeling and cause the release of endorphains also.
If it's bothering you that you can't go back to sleep, you could try drinking something warm...like tea or coca...or if that doesn't work, try sleep medicine. Just be careful if you try sleep medication.