How to hide "if DEBUG" code?

[J Krugman]

Production code often gets overwhelmed with fragments whose sole
function is to aid development (usually debugging) and has otherwise
nothing to do with the program's logic.  This makes it very difficult
to read the code, which in turn breeds its own problems (e.g. code
that is hard to read is also harder to debug, ironically enough).

Is there a simple way to instruct Emacs to hide such code?

Thanks!

jill

-- 
To  s&e^n]d  me  m~a}i]l  r%e*m?o\v[e  bit from my a|d)d:r{e:s]s.