Cause to reach a turning point or crisis. For example, Management's newest policy has brought matters to a head. The related phrase come to a head means “to reach a crisis,” as in With the last break-in, the question of security came to a head. These phrases allude to the medical sense of head, the tip of an abscess that is about to burst. [Mid-1500s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.