I have discomfort under my left rib cage at the bottom of it.?

have discomfort under my left rib cage at the bottom of it. if i press in on that area with my fingers quickly i can feel trapped air? like bubbles. i thought my lung was congested but now im thinking it is something outside the lung because i can breathe fine.but like i said it feels like trapped bubbles in that area.what could this be?