I also experiencing very similar symptoms. Tighness upper chest, restrictive feeling in breathing or at times, either with those symptoms or just on its own when it takes more effort in taking in deeper breaths with this constant feeling in needing to clear my lungs. It does produce clear phlegm as well, when active or exercising on my treadmill.
I may be good for a couple of months or so and then I get these bouts of symptoms appear, lasting days or weeks.
What did I do about it?
Had lung function test done. Showed normal and above 80%. Yes, i have heart disease but that is under good control and is counted out as I can exercise, hike and push myself without any Angina or heart related symptoms. BP is fine and my fitness level for a 68 year old is that if the top 20%. Tried the use of a ventolin but seems to have no impact, same as others have stated.
I am leaning more toward either an allergy or bronchial restriction caused by something other than an allergy. Exercise induced? Not convinced. So? In the mean time I am baffled by it as many are with similar experience with these symptoms. Especially when numerous including myself stated that tests done are negative. I am on a whole plant base diet, so doubt it could be from my diet. Never the less, there is still a chance that perhaps chemicals used on plants may set it off. People seem to get more issues these days than they did before. Environment, what we consume? It is hard pinning it down. Allergists are not cheap and not everyone can afford that. So? In the mean time I am assuming it's nothing serious as it has been going on for years, coming and going. Doctors are often not much help and just shrug their shoulders.