Okay so my little sister had said something funny and I started laughing but as soon as I started laughing my head go really dizzy and light headed, and I felt like my head gained 20 pounds and I couldn't support it and was on the verge of blacking out and am pretty sure I would have if I hadn't of stopped laughing at that moment. Does anyone have an Idea as to why this would happen? It's never happened before. Plus recently I've been getting dizzy, light headed, and randomly loose my balance often and that didn't used to happen before.