To cause or attempt to cause one to feel confused, exasperated, frustrated, or anxious. All the rules and regulations with this business are really starting to mess with my head.I don't know why you have to mess with his head like that. If you don't want to be in a relationship with him, just say so!See also: head, mess
mess with someone's head
cause someone to feel frustrated, anxious, or upset. US informalSee also: head, mess