Ok so I've seen a lot of questions on here about anxiety, and I know my friend has it, but I'm kind of confused on what it is. I know I probably sound really weird, but I don't really know that much about it. Is it an actual medical diagnosis? My friend tried to explain to me multiple times, but I never really got it. How serious can it be? How serious is it usually? Also what's a panic attack? What exactly is anxiety?