A disc is like a jelly bean with a gooey center. If the "shell" of the jelly bean is cracked, the jelly and the goo can ooze out. It can also ooze back in. Kinda like those kid's toys of the chicken with the gooey egg-blob that comes out when you sqeeze it, and goes back into the chicken when you let go. when your disc is under pressure it can squeeze out the goo, when the pressure is off the goo can go back into the disc's "shell".

Sorry, not a good description. But really, it's not the disc that moves, its the gooey inside stuff.

What you want to figure out is what is causing the pressure that moves the goo in the first place.

As far as not feeling normal and the decreasing heart rate: please call your doc or the on-call doc for his practice. If you can't reach him, call your pharmacist.