come to a head, to

To reach a point of intensity at which action must be taken. The issues that you're trying to ignore in your relationship will come to a head eventually, so you might as well deal with them now. Tensions in our community came to a head following the mayor's insensitive comments.

Fig. [for a problem] to reach a critical or crucial stage. At the end of the week, everything came to a head and Sam was fired.

COMMON If a problem or disagreement comes to a head, it becomes so bad that you have to take action to deal with it. Matters came to a head on Monday when he threatened to resign. These problems came to a head in September when five of the station's journalists were sacked. Note: You can also say that a particular event or fact brings a problem or disagreement to a head. The crisis is believed to have been brought to a head by demands from the bank. Note: This expression may refer to farmers waiting for cabbage leaves to grow together and form a head. Alternatively, the reference may be to a boil (= painful lump on the skin) forming a head (= white part in the middle) just before it bursts.

To reach a climax or culminating point. The analogy is to an ulcer or boil that has ripened to the point of suppuration, that is, bursting. Indeed, such sores were said to “come to a head” as early as the early seventeenth century. By then the term had long since been transferred to other matters (the OED lists the earliest figurative use of it from 1340). In 1596 Edmund Spenser, describing the state of Ireland, wrote, “to keep them [i.e., these affairs] from growing to such a head.”