I have noticed discomfort (mild pain) while pressuring my sternum(heart bone),and the pain continued for last two months.Sometimes, I can still feel it in the morning and even certain movements cause the same pain. If I take deep breath and pressure my sternum,I feel the less pain. I have no breathing problems. I have been diagnosed sino-bronchial syndrome 4 years ago,and also have some allergies (dust,pollen etc). I must confess that I've been smoking for about 3 months but I quit it 2 weeks ago,and I still feel the same pain.