Is this feeling part of sleeping?

i been having these feeling all the time and always wounder what it is.

I went to sleep and stay absolutely still without even moving any single my muscle. Then sometime later i begin to feel my blood going through my body (Normal) now here's the weird part - my mind starts to spin in circle again and again then it stop, after about 30 seconds i raise my arm and it's all numb.
Someone please tell me what it is.

PS: maybe it's that thing in the other post about "how to trick your body to sleep" or maybe not. Or maybe it's me using CHI...maybe

That is called sleep paralysis, spinning is common when you enter. You were very close to having a lucid dream, you should have waited longer. Its not dangerous or anything its all natural.

We have sleep paralysis so we don't kill our selves when we dream, so if you were scared dont be.