You could try to put cold ice over it to calm down the bruising and then use a cloth and damp it in hot water(warm water) and wipe the bruise properly so that the blood can circulate properly. If you are having troubles breathing then why to relax your muscle, because if you are tense right now it will only make things worse.
And if it really hurt go to the hospital, dont take any risks.
Cardiovascular disease would be the most likely as the oxygen taken in is polluted and enters the blood stream. Thus as it travels to the heart and throughout your body you risk disease.
