Scared...what Happens Next?

Last night I had a series of bad dreams but this one stood out to me the most...I was at a park I think doing a birthday party of some sort. Everything was all good till my little brother yells at me and says, "look!" My sister passed out...I kept trying to wake her up (me and my sister are really close) but she wouldn't wake up. I'm to the point where I'm crying and I don't know what to do..I keep shaking her and saying sister please wake up..please. She finally wakes up and we hug and everything. I tell her never ever scare me like that again. The last thing I remember her telling me is "how can i prevent it brother?"

My question is...What does all that mean?
Brother7 Brother7
22-25, M
Dec 1, 2012