my hair was on end

When someone says their hair was on end, what they mean to say is that they were very frightened by something they saw or heard, whether this was a scary story, a frightening news story on the television or witnessed something equally horrifying. Referring to a persons hair being on end or sticking straight up comes from the fact that many older movies show people with their hair sticking straight up when they are very scared or even surprised by something that has just occurred.