OTHER
There are no Wounds in D&D as defined in the rules. Damage causes whatever the DM wishes to describe it narratively. As such, healing is treated the same way. How it occurs is within the narrative control of the DM. One unified mechanic, Healing Surges, is used to cover a multitude of methods.
A Cleric's Healing Word may close wounds.
A Warlord's Inspiring Word may give the character the resolve to continue despite the pain he is in.
Since the earliest days of the game hit points have been described as a combination of physical toughness, skill, luck, resolve, etc. How those hit points are lost or gained have always been up to the DM to determine.