What causes people to sleep walk?

What causes people to walk and talk in their sleep?

• In the last few years I've had nightmares where I scream in my sleep. Another time I snatched my sister's pillow from under her head and started hitting her with it (I didn't hurt her at all). I've woken up standing at my bedroom's doorway, holding my bedding in my arms. Is there a way I can prevent myself from sleep walking and talking?

• Answer:

  Usually this is simply caused by stress.. it can do crazy things to your body :P it really usually isn't a big deal.. however though, if this were to continue, you probably should go have a sleep study done.. but unless it becomes a commonly occurring event for you, don't worry :)