In reply to jules699:
Being a medical expert when in forums, I'd say if it hurts wait a bit longer, though the back of the hand isn't the most used body part when climbing indoors, so crack on. Jamming may be a while longer tho.
I'm guessing you damaged a vein or something similar if it went proper funky colours and swollen as soon as it was done.
You could try ice for the swelling.
Oh and cursing the hold which got in the way mid move may help. If you use profanities, loud clear and confident should re assert your authority.