I wish I had potions in real life. On a more random note, how can your characters possibly be hurt without sustaining injury? If you punch someone in real life, all the damage that you do to them will be caused by injury, not vice versa.
I've always thought of HP as how close you were to passing out due to pain, and injury prevented recovering that HP due to the pain of, say, being violently jerked around, as you are hit, the would brushing against your clothing, etc. But I've never understood how a person with low DEX couldn't wound you with a sword. o.o