Hi there, I am 17 years old and recently have been experiencing very unusual symptons. When I sit on a hard surface I can feel the bones in buttocks pressing up against the seat, I am not particularly thin and I haven t lost any weight , I have had this feeling for a couple of months I would say now. Also, the bones in my waist (below the upper part of pelvis ) seem to have got more prominent. Also, I can feel something, it seems like the bottom of my spine, when I sit on a hard surface. All are very uncomfortable and I m extremely confused. Please please help me, thank you.