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Related to lose head: loose head
lose (one's) head
To lose one's composure and act emotionally or irrationally. You need to calm down before you talk to Larry. You don't want to lose your head before finding out his side of the story. I'm sorry, I lost my head out there. There's no excuse for what I said.
lose one's head (over someone or something)
Fig. to become confused or overly emotional about someone or something. Don't lose your head over John. He isn't worth it. I'm sorry. I got upset and lost my head.