I have had chronic post nasal drip for years. I had a Nurse practitioner perscribe anibiotics but it's still here. It gets really annoying because I am a singer. The phlegm seems to hit my vocal chords right in the mid range of my voice. Last week I auditioned for a choir and of my mid range notes literally didn't come out because I had so much phlegm, which made me panic and get nervous. I bombed the audition! I've mentioned this to my current Dr. (who is a CFS specialist) and she said its common for patients to have chronic respiratory problems and it may be that our immune systems over react and cause these problems. Maybe an auto-immune type of response? I take muxinex and the netipot, which help some. If anyone has any further suggestions that would be great!