The amount of time it takes to heal, to suture, to remove glass, all the action become quicker as your skills raise.
If it doesn't seem like much, it will save your life when you are badly injured and are bleeding to death because you can't perform the actions quickly enough.
At level 10, you zoom through the actions of giving yourself treatment and the healing time seems greatly reduced.
It does time a long time to grind though.
As soon as I'd heal up from wounds, I'd walk barefoot on broken glass and jump through windows with the broken glass still in place - it was a grind but I'm glad I did it.
I do like Extrema's suggestion about chance of failure being involved with each medical action.