I have the phlegm thing. This is disgusting, but a few months ago it began pretty suddenly. Every morning I'd get up and hock a disgusting loogie. It was like it built up in my throat overnight just waiting to get spit out. I guess we should be thankful for this...we could swallow it in our sleep (could cause nausea and even a vomit) or it could drift back down into the lungs causing problems.
Do you smoke? I attribute my problem to smoking and not anxiety. I also get the tightness in the chest, but attribute that to the smoking, too. It could be anxiety, though, or a combination.
I told my doctor about the sudden loogy issue and he didn't seem concerned. Took an x-ray and listened to me through the stethoscope, said I was fine (for a smoker).
But it could be lots of stuff: anxiety, air pollution, allergens or other particulate matter in the air...who knows. Have it checked out if it worries you.
For side-effect information look up "Physician's Desk Reference" in Google. The company who publishes it offers one for doctors ($$$), and another that's for patients (free).