The sides of my neck feel like they are swelling up or putting pressure outward...It is very uncomfortable and I feel like I can't breathe! They don't hurt, just feel like they are puffing up with air and are going to burst or something! The feeling is also in the space right in the center of the collarbone/bottom of the throat. I don't know, it's like it's all full of air...Sometimes a lot of heaviness on my chest...I'm 20 yrs. Old, female, generally good health(as far as I know). It's really scaring me! Please someone help!