I have been coughing up a greenish-yellow phlegm on and off for as long as I can remember (over 20 years). The only reason I ever cough is because I can tell There is something in the airway and I want to remove it. This discharge is very sticky and is difficult to expell. It generates from the chest and seems to loosen up after a workout or a physical activity. I don t see doctors often but I have explained tis to a few different doctors that I have seen over the years. They always poo-pooh it and if a test is run there is never anything that shows them a path, so it goes untreated. I have been perscribed antibiotics over the years for sinus infections but this coughing phlegm has persisted although usually minimal. Is this something you have heard of and what can I say (if I need to vist another doctor) to get a serious directive?