I've got an odd sort of acute pain in my lower right chest. It's right beneath the breast, and it feels as if the rib itself is in pain, or perhaps the connective tissue. It's an acute pain as I mentioned, and noticeable mostly in the second half of the day, which I attribute to strain perhaps.
It honestly feels like a pulled or sore muscle. It's on the right side which is why I'm not concerned. This is actually the second "episode". I had this happen last week for the first time, near the weekend I believe. It came on suddenly one afternoon. It lasted that day but I believe it went away for bed time, then returned the next day, then faded. I hadn't noticed it for a few days and now suddenly it's back.
I can take fairly normal breaths without feeling too much pain. I did have an odd - though I think unrelated - episode this morning for about thirty seconds where the left side of my chest hurt in about the same area. That was far more severe and did restrict breathing until I macho-ed through the pain. It went away very quickly.
Inhaling deeply OR exhaling deeply aggravates it. Certain positions make inhaling more painful, like curled up positions. Stretched out positions seem to help, further suggesting to me it's some kind of muscle or tissue damage.
There is NO tenderness at the site. Rubbing my rib and the surrounding area hurts no more than poking any of my other ribs.
And of course, now that I'm typing this, it's going away for the night

I'm serious. In the time it took to fully write this post and check it for errors and add things, the pain is gone.
Frustrating! A good friend suggested it was indeed muscle pain the first time it occurred last week.