There was also this nagging thing that Beth & I called "Cold Run Lung" where we would have achy chests & a naggy cough after running in the cold air. I've always experienced that but in the past year or so it has happened even when the air isn't cold. It was a more frequent problem & the achy feeling became more like a tightness. The tightness would settle in while I was running, quit when I stopped, & then come & go for several hours after I was done with my run.
I didn't like it.
So I went to the doctor. We talked it over & she gave me an inhaler to use for what she called "Exercise Induced Asthma". I've been using it for a couple of months & I went back in for a follow up appointment last week.
The inhaler has been helping. The tightness in my chest rarely happens now while I run. But sometimes later it hits me again. We discussed what it could be - gas (given my burping propensity, this could be a definite possibility), a muscle/skeletal inflammation, bronchial spasms, or a heart condition. She listened to my heart for quite some time & said that she thought she detected a fast beat sneaking in every little bit. This can explain the tightness, it can also cause lightheadedness or momentary weakness. It's generally a benign condition but requires testing to confirm the diagnosis & confirm that it is harmless.