Post-traumatic stress disorder (PTSD) is an anxiety disorder that’s caused when a person is exposed to a traumatic event like assault, an accident, or abuse. A traumatic event can develop into PTSD if a person experiences a traumatic event and is unable to cope or process it in a healthy way.PTSD is characterized by anxiety, panic attacks, depression, nightmares, and flashback memories that have to do with a particularly traumatic event. It may also involve avoidance behavior that’s related to places and situations that may trigger uncomfortable memories or flashbacks.These flashbacks often contribute to anxiety and a feeling of isolation. PTSD is often associated with veterans that have seen combat, but it can happen to anyone that experiences any type of frightening scenario. It can come from both momentary events like a car accident, but it can also come from prolonged exposure to trauma like years of abuse.PTSD is thought to be related to the fight-or-flight response, which is an important function of the brain that helps to protect you from harm. Fight-or-flight floods the body with chemicals that boost your energy and prepares you to run or fight a threat. You may feel this response anytime you’re watching a movie, and there’s a jump scare.You suddenly become more alert, your heart starts beating faster, your breathing increases, and you become extremely vigilant. People who have PTSD may experience a misfiring of that response. Small triggers can cause flashbacks to a traumatic event that causes the fight-or-flight response to fire.This can cause you to panic at inappropriate times, like when you’re trying to sleep or in the middle of a social interaction.