I have had extreme shortness of breath, tightness in my chest and very slight burning in my chest. I have had an upper G.I whcih was neg., three chest ex-rays whcih also were neg. i also had an echo, and stress test, both were neg. My Dr. has told me that I have GERD and I am taking acifix 20mg 2x per day. I have had asthma since I was 10 y/o I am now 33. I recently had a pullm. function test and was told my shortness of breath was not from asthma and that my breathing was at 188%. I smoked for 7 years approx 1/2 pack per day. Smoked Marjuiana about 5 times per week for about 5 years. i stopped smoking cig. 14 months ago and smoke marj. about once a week. My question is: is a lung x-ray accurate? Can GERD cause this many symptoms? Can GERD be this bad? My Dr. also told me that it can take 1-2 months for acifeix to work, true? I would appreciate any feedback. Thank you!