How to Turn on the Health Bars in "World of Warcraft"by Scott Sherman ; Updated September 22, 2017
Being aware of the health of allies and enemies is an integral component of "World of Warcraft," especially to a player who is often on the losing end of a battle. Displaying health bars over the heads of both allies and enemies in the form of nameplates will let you quickly tell at a glance who is thriving and just barely surviving. By default, only enemy health bars are enabled at a bare bones level; enabling allied health bars and other custom options will prove invaluable for both novices and experts alike.
In-game, hit "Escape" on your keyboard to bring up the main menu, then click the "Interface" button followed by the "Names" tab. The Unit Nameplates section in the Names tab will enable you to turn on health bars: Selecting "Friendly Units" will turn on nameplates for friendly units, and selecting "Enemy Units" will do the same for enemies. If you still do not see nameplates, it's possible they were disabled through a keybind. The default keys to enable nameplates are V for enemies, Shift-V for allies, and Ctrl-V for both.
You can also alter the on-screen orientation of nameplates using the Nameplate Motion Type drop-down menu. "Stacking" will align nameplates vertically when they contact one another, "Spreading" will do the same except align them horizontally, and "Overlapping" will not attempt to align nameplates, but instead allow them to cover each other.
Changing the Default Nameplate Keybinds
If you aren't happy with the default key bindings for nameplates, access the main menu and select "Key Bindings." Choose the "Targeting" tab and scroll down until you see these three listings: "Show Enemy Name Plates," "Show Friendly Name Plates," and "Show All Name Plates." Assign new key binds and click "Okay" to save your changes and exit.