I have no idea if this is a serious condition or if it s reversible, but it s something that has been happening to me since, probably 14. I m 18 goig 19 this year. Anyway, from time to time when I breathe in, there s something in my heart that seems to get stuck. At least it is in the place where my heart is. It s like I can t breathe in totally, because it starts hurting after a reach a point in the streching (of the lungs?) I could go all the way, but it feels like it s going to rip something, and it isn t pleasant when I do it by accident, as in an unpreoccupied yawn. It s a sting. It s like something, which to me feels like the heart, gets stuck on an upper rib or SOMETHING, but I can t breathe totally, as you do when yawning. I can breathe out all the air and then slowly take it in, and some times it goes away, sometimes it s still there. And I find myself having to breathe in small intakes for a while. Does someone know what this is?