Can you hide your healthbar?

I'm at work so i cant check but my friend who plays said he has no health bar with the options menu etc... Did he hide this by mistake? How can you bring it back?

Thanks

Somehow people do occasionally hide the status window, even though it isn't flagged openable or closeable. The only way I know of to bring it back is the slash command: /windowresetall
Have him type that in his chat box and hit enter.

thank you

/show health should reveal it.