hit/touch a nerve

touch a nerve

or

touch a raw nerve

COMMON If something that you say touches a nerve or touches a raw nerve, it upsets someone, because you have mentioned a subject that they feel strongly about or are very sensitive about. I realised I had touched a nerve with my remarks. Buchanan's speech touched a raw nerve here at the Capitol. Note: You can also use other verbs such as strike or hit instead of touch. She seemed to strike a nerve when she asked Dr. Lowe about his past life. His remarks clearly hit a raw nerve with congressional Democrats.
See also: nerve, touch

touch (or hit) a (raw) nerve

provoke a reaction by referring to a sensitive topic.
See also: nerve, touch

hit/touch a (raw) ˈnerve

say something which upsets somebody because they are very sensitive about that subject: You touched a raw nerve when you talked to the manager about the need for better communications within the company.
See also: hit, nerve, touch