Violence by an intimate partner is linked to both immediate and long-term health, social, and economic consequences. Factors at all levels — individual, relationship, community, and societal — contribute to intimate partner violence. This type of violence can occur among heterosexual or same-sex couples.
Preventing intimate partner violence requires reaching a clear understanding of those factors, coordinating resources, and fostering and initiating change in individuals, families, and society.
Types of Intimate Partner Violence
NIJ has often partnered with the Centers for Disease Control and Prevention (CDC) on the issue of violence against women, in particular by cosponsoring the National Violence Against Women Survey (NVAWS). The CDC's National Center for Injury Prevention and Control, which spotlights injury and violence prevention topics, defines four main types of intimate partner violence: 
- Physical violence is the intentional use of physical force (e.g., shoving, choking, shaking, slapping, punching, burning, or use of a weapon, restraints, or one's size and strength against another person) with the potential for causing death, disability, injury, or physical harm.
- Sexual violence can be divided into three categories: (1) the use of physical force to compel a person to engage in a sexual act unwillingly, whether or not the act is completed; (2) an attempted or completed sexual act involving a person who, because of illness, disability, or the influence of alcohol or other drugs, or because of intimidation or pressure, is unable to understand the nature or condition of the act, decline participation, or communicate unwillingness to engage in the act; and (3) abusive sexual contact.
- Threats of physical or sexual violence communicate the intent to cause death, disability, injury, or physical harm through the use of words, gestures, or weapons.
- Psychological/emotional violence traumatizes the victim by acts, threats of acts, or coercive tactics (e.g., humiliating the victim, controlling what the victim can and cannot do, withholding information, isolating the victim from friends and family, denying access to money or other basic resources). In most cases, emotional violence has been preceded by acts or threats of physical or sexual violence.
Stalking is often included among types of intimate partner violence. Stalking generally refers to harassing or threatening behavior that an individual engages in repeatedly, such as sending the victim unwanted presents, following or laying in wait for the victim, damaging or threatening to damage the victim's property, appearing at a victim's home or place of business, defaming the victim's character or spreading rumors, or harassing the victim via the Internet by posting personal information.  As with perpetrators of physical and sexual violence, stalkers may be motivated by a desire to exert control over their victims. Stalking and intimate partner violence may co-occur.
[note 2] Tjaden, P., and N. Thoennes. Full Report of the Prevalence, Incidence, and Consequences of Violence Against Women: Findings from the National Violence Against Women Survey. Research Report. Washington, DC, and Atlanta, GA: U.S. Department of Justice, National Institute of Justice, and U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, November 2000, NCJ 183781.