Dropbox Low Disk Space Error on Mac OS X

Hello Techyv users!
I am using a Mac and for some reason, I keep on getting the following message, but I don't know why!

Low disk space
Dropbox cannot sync unless you free
some disk space on your computer.
Low Disk Space error on Mac OS X
A drop box shows up saying I don't have sufficient disk space; I know for a fact I do! Any ideas?
