Usually, no, because it won't be staying there too long a time. When everything's working the way it should---and it's not, like, a ridiculous amount of bleeding making the bruise---the blood that's trapped there will kinda be broken down and reabsorbed. There's places where internal bleeding can cause some serious problems what with the pressure and the swelling, but bruises are generally just minor injuries. Even the worst of the normal ones. I've seen some impressive.