When I do my airway clearance late morning I cough up a combination of colored mucus and white foamy stuff. The addition of the white foamy stuff started happening about 1.5 years ago? Maybe 2? Prior to that I never had it. I have asked my pulmo about it a few times. He does not seem to know but did say it could be from air getting into the nebulizing process or some such thing. I know that sounds confusing but the white foamy stuff does seem full of air. But the more I hear and read it seems like acid reflux is a known cause of it. I also clear my throat a lot. But wonder if that is from reflux or simply the food sort of sticks to the throat due to the mucus/infection?