I have a problem that has been going on for months now. Mucus build in my lower throat. I can feel it rattling if I breathe through my mouth but not if I breathe through my nose. My sinuses are clear and my lungs seem fine. I cough up clear or occasionally light yellow tinged mucus. Worse at night when I am horizontal. I live in Florida where we have nearly year round pollen. Taking Zyrtec and Flonase. Not sure what to do about this.