I have an underactive thyroid for around 2 yrs. now approx. I got where i could not breath Sunday but after i got cooled off opened door i was okay and could breath alittle better. Monday morning I got up for wrk. about 4 am and was having chest pain and trouble breathing i went on to wrk. and it gave me some promblems so after wrk. I went to the ER and they done blood wrk. and x-rays and told me everything looked normal not to worry about it, and tould me to take 20 mg. of pepcid 2 times a day. I got up this morning and at wrk. got out of breath and chest discomfort so I came home took my meds. and laid down than at 5 i took the pepcid and now my neck fills swoolen and hurts alittle when i swoller should this be a concern and what can i do about this??