Today on my run, just a routine easy 6 miler, I started noticing some foot pain. It started out more on the bottom of the outside of my right foot, just to the outside of the arch, and at that point (maybe a couple miles into the run) it wasn't bad at all; it just kinda felt like it might if you had stepped on a rock or something and bruised your foot a little. However, as I got near the end of my run (around the 5 mile mark or a little before) it suddenly started getting pretty bad, and it seemed to have shifted to the side or even side to top of my foot. I struggled to make it through that last mile or so, and as soon as I stopped it got even worse and I found myself hobbling back to my door. Now I'm still having difficulty walking, and it's just so weird because it came on so suddenly. I had had NO pain or signs of injury troubles whatsoever until this morning. To me the sensation this causes feels like bone pain, not muscle, but I don't see how that can be (and I sure hope it isn't) since to my knowledge stress fractures don't just pop up overnight. The pain varies in severity; most of the time walking around it's just there enough to make me walk gingerly to avoid hurting it, but occasionally, often seemingly if I step in a particular way or too forcefully, it'll hurt like crazy- sharp, very sudden pain. Both when running this morning and when walking it has semed to help to stay on the balls of my feet, trying to kinda avoid putting much weight on that area. Also, it doesn't hurt to the touch, just when I put weight on it. Has anyone had anything like this before? Any ideas of what it is? Stress fractures can't appear without warning like that, right? Any feedback is much appreciated! Thanks!