Question for the hive mind: I have a very long document ...

Question for the hive mind: I have a very long document in Word 2004 for the Mac (version 11.2) (I know, but I can't upgrade Word right now). It's passed through several different hands, and at least one of them has done something to it so it's inserting an extra blank line between paragraphs. Any suggestions has to how I get it to stop doing it? I've checked what feels like every style and format setting in the program, and nothing works.

Thanks in advance for any help!