Hello Sugoya,
I am sorry that you are experiencing pain. There are multiple reasons that could be the culprit of your pain. I am far from an expert and with that in mind the following is some general information.
Obviously when you breath you are expanding your lungs which could be causing pressure on an inflamed or diseased part. Mid lower back could actually be referred pain, meaning felt in one area but originating in another. If that is the only symptom you are having I doubt it is actually spine related. Again this is just my personal opinion.
Therefore that leaves ribs, organs, muscles or similar tissue structures. Your diaphragm or ribs can cause mid back pain.
Nerves to the organs of the pancreas, liver, and adrenal glands travel out from the med section of your spine. The gall bladder, and small intestine nerves are also from the mid-back as are the ones that go to the stomach or digestive tract. So you can understand how difficult it can be to diagnosis your symptoms.
Knowing the exact location of your pain will help your physician in his/her diagnosis. Did you know that lower back pain is the second most common reason people consult with a physician. The first most common reason is a cold.
My PCP is an Internal Medicine Doctor of Osteopathy, they function very similar to MD's. However their have a bit more education and training in the significance that proper body alignment plays in ones over all health and well being. I suggest you see a DO but than I admit I am bias.
Please do not ignore your symptoms. Make an appt with a physician for a thorough clinical evaluation. It could be nothing serious but seeking a medical opinion is always your best bet. I wish you the best of luck and hope that you will update us on your outcome.
Take Care,
~Tuck
Hello Sugoya:
I'm sorry that you're experiencing this. You are not going to find that answer here. It sounds like you really need to be seen by a Physician. Only they can diagnose you.
Please make an appt. to see one.
My best,
Mollyrae