Dear Doctor, I have had a productive cough for approximately 3 months now. I have been to two different doctors on 3 seperate occassions. Each time, an xray was taken of my chest which was always clear. I cough up thick mostly yellow phlegm . As recently as this morning, I woke up actually gagging and vomiting up phlegm. Doctors have prescibed antibiotics including levoquin, inhalers, and steroids ( prednisone ). Nothing has seemed to work at this point. I am getting ready to see another doctor, but ask that he refer me to an ENT. What do you think could be going on with me? Thank you in advance for your response.