Hysteria is the fourth studio album by English hard rock band Def Leppard, released on 3 August 1987 through Mercury Records and reissued on 1 January 2000. It is Def Leppard's best-selling album to date, selling over 25 million copies worldwide, including 12 million in the US, and spawning seven hit singles. The album charted at #1 on both the Billboard 200 and the UK Albums Chart
The album is the follow-up to the band's 1983 breakthrough Pyromania. Hysteria's creation took over three years and was plagued by delays, including the aftermath of the 31 December 1984 car accident that cost drummer Rick Allen his left arm. Subsequent to the album's release, Def Leppard published a book entitled Animal Instinct: The Def Leppard Story, written by Rolling Stone magazine Senior Editor David Fricke, on the three-year recording process of Hysteria and the tough times the band endured through the mid-1980s.