This chapter explains what constitutes intimate partner abuse and describes why battered persons have feelings of powerlessness. It discusses how violence is often used as a means of gaining a power advantage over the abused partner. The chapter examines the dynamics of intimate partner abuse and relationship violence. Partners who share power or are equals in the decision-making process have the lowest level of both conflict and violence. Intimate partner violence (IPV) is violence committed by a spouse, ex-spouse, or current or former boyfriend or girlfriend. IPV occurs among both heterosexual and same-sex couples. The Focus box “Acknowledging Domestic Violence” indicates the turmoil that partner and relationship violence is generating within the medical profession. The impact of repetitive violence on an individual’s health often brings domestic violence into the medical setting. The image of opening Pandora’s box was used by physicians to describe their reactions to exploring domestic violence with patients.