break (one's) balls

break (one's) balls

vulgar slang To exert oneself to the utmost degree; to put forth the maximum amount of effort or strain. Because of the slang reference to testicles, it is usually (but not solely) said of or by a man. I've been breaking my balls trying to get the new software ready by the release date. Don't break your balls getting over here, there's no rush.
See also: ball, break