I m fifteen, and the other day I noticed this awful pain in my hips. It started during marching band, a new instructor made us run, and then bounce around the field on our feet . Eventually I got tired, and it got so difficult to breathe. I had to hyperventilate just so it wouldn t hurt my chest and the left side of my torso and back. Once I recovered and stood up, there was this horrible pain in my hips. It hurts to sit or stand, walk, run, and even shift my weight whilst standing. If it helps, maybe, I have flat feet? I m not sure, but it really hurts and I have to repeat the exercise all week...what s wrong, or what can I do to stop the pain?