my health bar disappeared how do i fix it to get it back

Is the portrait of your character still there or is it just the red bar that says health?

 

Because it's possible you unclicked it under the Interface editor.

Not exactly sure which bar you're talking about, but it's 1 of 2 things. 1st: Go to Interface Editor and click on the thing(s) that are missing and check enable. 2nd: Go to preferences>nameplates and check the see health bar option. Edited February 17, 2013 by Strainge

If it's the portrait along with the health and resource bar that's gone, then restart the game to get it back, it's a bug and happens from time to time, might have to run repair tool if restarting doesn't work.

 

It happens sometimes to me that the whole frame with my portrait and everything disappears even though it's enabled in interface editor and the only fix is to restart the game, sometimes I've had to run the repair tool to get it fixed.

I've had the health bar display as empty on the nameplate for my character. Usually I just go into preferences and make the nameplate go away, apply, and then put it back and that restores it.

 

Was that what you were describing?