I Have A Slight Back Pain In My Lower To

I have a slight back pain in my lower to middle portion of my back. I hardly ever get back pain because I go to the Gym and do a few back exercise so my back won't kink up and get sore. When I have avoided the gym for a few weeks,....then I get sore in my back, but only a little, and only for a day or two, easily taken care of by a little back rub ointment. And when I applied it for this particular pain, the muscle rub did not take the pain away. So I don't think this pain is muscular in
nature. Here is one symptom: If I inhale strongly, the pain comes with the inhalation of air. A pressure builds up in the middle of my back, across the back, and also the lower back. When walking around normally, I do not have the pain.