Post-traumatic stress disorder (PTSD) is an intense emotional and psychological response to a recent or past traumatic event. A traumatic event is life-threatening and very disturbing or stressful; PTSD can develop after a person has lived through or seen this kind of event, such as rape, a natural disaster, or war.

Symptoms of post-traumatic stress disorder include:

• Reliving the event through dreams (nightmares) or while awake (flashbacks).
• Not being able to feel or express emotions toward family, friends, and loved ones (emotional numbness).
• Avoiding any reminders of the event.
• Being easily angered or aroused, "on edge," or easily startled (hyperarousal).

Treatment for post-traumatic stress disorder includes counseling and medicines, such as antidepressants and antianxiety medicines.