Ever since I can remember, I have had a flat spot in the upper-middle region of my spine (about where the thoracic region begins). It looks and feels as if one or two of my thoracic vertebrae are missing. You can see/feel the rest of my spine perfectly fine and then there's an obvious flat spot. It's never been associated with any pain or anything until recently; for the past month or so, I've had bruise-like pain on and around the flat area. It only hurts when I stand or sit straight up or if I'm laying on my stomach and attempt to roll over or get up. I don't know if the flat area is the cause of this pain seeing as I'm 20 and this is the first time it's ever been in pain, but what I am really concerned about is why do I have a flat spot? Does anyone else have this or know anything about it? Your help is appreciated.