From WebMD http://www.webmd.com/sleep-disorders/night-waking-insomnia-13/rm-quiz-night-waking?ecd=wnl_wmh_080813&ctr=wnl-wmh-080813_ld-stry&mb=UpsIy17V08ym9SHgdyYhx2dEpmNqbUHLgHWMtUj%2fIK4%3d