When people have PTSD, they often avoid people, places, and things that remind them of the traumatic event. Avoidance can be a healthy coping mechanism in situations where there is real and actual danger. However, avoiding relatively safe situations, as well as thoughts and feelings related to the trauma, can perpetuate PTSD symptoms. Exposure helps a person to face their fears and learn that they can overcome them and that most situations are not dangerous. It also helps the person to learn that thoughts and feelings are not dangerous as well, even though they are disturbing and uncomfortable to manage.

The main components of Prolonged Exposure are in-vivo exposures and imaginal exposures. In in-vivo exposures, a person puts themselves in safe situations that they have been avoiding. This may include public places, smells, songs and scenes in movies, and other situations. When a person does this, over time, their anxiety reduces and they build confidence that they can handle different situations.

The second main part of Prolonged Exposure is imaginal exposure. In imaginal exposure, a person tells their trauma story throughout the session, and re-hears this story on a daily basis. While intense and scary at first, the story eventually becomes less distressing to talk about. A person may learn new perspectives of the trauma and no longer feel like it is controlling their life. Although difficult, this is a major step towards healing PTSD.