Just my input...
If you have gerd, it CAN give you breathing problems. I know allot about this issue, and have done allot of research, school ect.
If you have GERD and breathing problems, the 1st thing you should do is get a lung x-ray, and a pulmonary function test, and check your blood oxoygen level. This, depending on your age, and general health, can rule out most lung disease's and asthma. If the tests are not normal, then you can go from there.
2nd, you have to have a endoscopy to see how bad your reflux is. A barium swallow, is a WASTE of time, but is a good test for some other things....
If you do indeed have evidence of gerd, then the breathing may be caused by it. If you have a hitaus hernia, that will DEF. make your breathing worse. If you have the hernia, you need to LOOSE weight. If you dont, then your gonna have to deal with it, or have surgey.
If you are someone who hacks up mucus allot, burps, or feels the food coming back up. Then there is a good chance that GERD is casuing your problem, in the light that you have had the lung- pulmonary - heart tests done.
There are many articles, about GERD casuing undiagnosed breathing problems.
GERD can wosen asthma, or bring on adult asthma. But its fixable.
if you are on medicine for GERD and it dosent work, try another medicine.
The best drugs are nexium, protonixs, and my favorite Zegird. they all have side effects, but nothings going to be perfect.
The best thing to do for acid reflux is to loose weight. it will take time, btu make a huge differece.
2nd, is eating selection and habits.
If you have a hitial hernia, and you over eat just a little bit, dam right you are not going to be able to breathe. dont eat so much then.
90 percent of people with gerd, do not loose weight or change there eating habits, and thats why they dont see a change.
There are people where diet and medicine are not enought, but thats a small population.
Even mild gerd can cause symptons that make you feel like your majory sick, where in reality, you'll be ok.