Dear Patient,
i am guessing with "breast bone" you mean the middle bone in the chest, called sternum?
Let me lay out some possibilites:
1.) It can be a heart problem or lung problem, to be further examined by x ray and ekg to rule out coronary hert disease or a lung condition.
2.) It can be a stomach or oesphageal problem like
acid reflux, best to be further examined by a gastroskopy. Also an
ultrasound of the
gall bladder,
liver and
pancreas is advisable to rule out any conditions like gallstones or abdominal inflammations.
3.) if the above possibilities are ruled out, it can be a local inflammation of one of the small joints which connects the sternum with the ribs. Your gp or orthopedic doctor can check that by clinical examination (if the pain responds to pressure on the bone for example)
Please discuss these possibilities with your local md to proceed further on finding the cause to get you the right treatment.
Hope this is helping you , if you have any clarificatons you can get back to me, if this was helpful please kindly rate my answer. Best regards