If I could be your angel
(Your angel, your angel)
Protect you from the pain
I'll keep you safe from danger
You'll never hurt again
— Natasha Bedingfield, "Angel"
A long time ago a woman sat down at her desk and thought "How can I best combine my maternal and nurturing instincts with my massive personality disorder?" Thus the genre of hurt/comfort was born.
Snape: Hurt 'n' Comfort - I nearly died
Hermione: Hurt 'n' Comfort - ran to his side
Snape: I cut a vein (careless of me)
Hermione: Found a Snape, pale as could be