Head injury, as your head is your skull, damaging your skull is very serious as your brain is located there and damaging your brain could probably kill or limit some abilities
B. Old Stone Age.........................
1. Epidermis
2. K<span>eratin
3. D</span><span>ermis
4. A</span><span>cne
5. B</span><span>ody odor
6. W</span><span>ashing
7. Ea</span><span>rdrum
8. E</span><span>ar canal
9. W</span><span>ax
10. O</span><span>ssicles
11. C</span><span>ochlea
12. E</span><span>arache
</span>13. E<span>ar drops
</span>14. E<span>ar plugs</span><span>
</span>
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.