what is it?

My daughter of 17 , has got a persistente cough  for more than two years , now she started to bring solid white stuff.
  in the xray she took as come out clear , so what  that could be?



This discussion is related to AM Cough??.

[Sunny602]

Does she have allergies? The reason I ask is that a post nasal drip would do that, cause coughing and bringing up white'ish phlegm.
I hope that you find the answer soon, all of this sounds very frustrating...Sunny