I have 'allergy induced asthma', and the causes are dust, mold/mildew and drastic changes in weather.
It comes in quite handy when it's time to vaccuum!
I have a tightness/discomfort in my chest and nasal congestion. Like you, I'm bad about taking meds (just hate to take the chemicals!), but if you don't keep it under check you can have lots of bronchitis.
Try to zero in on what is causing it, and you can avoid a lot of problems. Find a good allergist and they will do the tests to tell you. It's really worth it.
Good luck, and feel better!