Wowpedia
Wowpedia
229,727
pages

A number of Player abilities and talents cause reduced healing debuffs that reduce the effectiveness of healing by a certain percentage. They are sometimes known as [Mortal Wounds] debuffs, after the Warrior's effect.

Demon Hunter
Hunter
Monk
Rogue
Warlock
Warrior

NPCs

Some other sources of reduced healing effects (particularly by NPCs and Bosses) include:

These boss abilities block healing completely:

Healing dealt

There are also debuffs that reduce the effectiveness of healers to heal others.