I get this costo thing quite often and not always associated with a cold virus. I live with post nasal drip and it drains down my throat and cause junk in the bronchial tubes. My peak flow and pulse-ox are totally normal. Breathing sprirometry tests are good. So, the pulminologist says to just up my steroid inhaler, take guaifenissin and tylenol for the pain (can't take NSAIDS because of tummy issues). He also said that this chest wall thing could be arthritic, although I think it is the pectoral muscles. Please, if anyone else gets costochondritis - please let me know how you treated it and if it made you winded a little when walking alot. Doctor says when the chest wall is inflamed it can cause breathing issues too.