I put a forget load of micro-fractures up the right side of my right hand by punching things. Pinkie and Ring finger knuckle hurt to touch and move on a consistent basis.
Things I've punched:
Dry Wall
My monitor
PS3
Wood Log
Metal barrel
Concrete wall
Bed
200 IQ. Will most likely regret everything I've punched when I turn 30.
You're punching wrong. One of the first things they teach you if you're learning to fight is to angle your punch so you never hit with your fingers or ring/pinkie knuckles.
You keep the knuckles of your index and tertiary fingers lined up with the bones of your wrist and arm, that way you're absorbing the force using your strongest bones and causing yourself the least amount of damage.
I punch things like walls, doors, metal carts, etc. all the time and it hurts bad if you hit at the wrong angle. I've punched my knuckles bloody before, and there are dents in the back of a metal door to serve as a reminder of this.
Anyway, I've never personally had anything bad enough that I had to go to the hospital or anything, but I've accidentally sliced my hands open on many occasions.
I once slipped with a very sharp knife and sliced the side of my thumb wide open. I probably should have gotten stitches for it, but doctors are expensive. I didn't even go when it got infected, I just used some antibiotics we had from when the dad cut off the tip of one of his fingers off at work. I still have the scar.
Interestingly enough, once it had stopped bleeding, I took a closer look at it, and could see where I had almost cut into a blood vessel, so it was almost way worse than it was.