I have read conflicting information on whether GERD can actually cause shortness of breath. I'm 38, male, smoker, placed on Prilosec last week by my GP. Since I began taking the Prilosec (20mgs per day), I've had several episodes of disturbing shortness of breath...they happen at different times of the day and aren't associated with any physical exertion. I wasn't actually choking or gasping for air, but my chest definitely tightened and every breath felt very shallow.