Hidden Labels in Form

I have a form with many labels. I was going through the form to renumber the labels and I have a few labels that I cannot change the Label number because there is another label with the same label number. I suspect that I put a label in the form an did not add any text to the label and now it appears to be hidden. Any ideas how to find the other labels without any text?

Cheers,

Many Thanks. That solved it.