Why Do Flashbacks Happen? Causes of a PTSD Flashback

The causes of PTSD flashbacks are complex; they also tend to be individual. Learn why PTSD flashbacks happen and their causes on HealthyPlace.People who suffer from posttraumatic stress disorder (PTSD) quite understandably want to know why PTSD flashbacks happen. This is because PTSD flashback symptoms can create a completely immersive experience wherein it feels like you’re living through the trauma that caused the PTSD. These flashbacks can be very frightening.

As to what causes a PTSD flashbacks, read on.

What Is a Traumatic Event that May Cause PTSD Flashbacks?

Most people will experience trauma at some point in their lives. Approximately 50% of women and 60% of men experience trauma. However, the vast majority of these people will not develop PTSD. Posttraumatic stress disorder has a lifetime prevalence of 8% (higher in women than in men).

According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), the causation of PTSD includes trauma that is caused when:

“The victim was exposed to actual or threatened death, serious injury or sexual violence in one of four ways:

  • Directly experiencing the traumatic event(s)
  • Witnessing, in person, the event(s) as it occurred to others
  • Learning that the traumatic event(s) occurred to a close family member or friend
  • Experiencing repeated or extreme exposure to aversive details of the traumatic event(s); this does not apply to exposure through media such as television, movies, or pictures”

Note that in order to be considered PTSD, the flashback must not be caused by the physiological events of substance use or other medical condition.

People can experience repeated traumas and be at greater risk for more severe PTSD symptoms. Long-term, severe abuse or multiple traumas can cause an illness known as complex PTSD (C-PTSD), also known as disorder of extreme stress not otherwise specified (DESNOS).

Triggers that Cause PTSD Flashbacks

Once a person has PTSD, flashbacks can happen. Flashbacks are a type of re-experiencing of the trauma. When a flashback happens, it is typically triggered by some kind of experience. While, initially, it may seem like flashbacks are random, once you start to look more closely at them, you can start to see that they are, in fact, triggered by something.

The cause of a PTSD flashback can be a trigger from any of the senses. Even a smell or sound can cause a flashback. Examples of triggers that could cause flashbacks for someone with PTSD include:

  • If traumatized by a car accident, traffic or being in a car may be triggering.
  • If traumatized by a burglary, the sound of breaking glass may be triggering.
  • If traumatized by combat, a loud noise (such as a car backfire) may be triggering.
  • It traumatized by an assault, the smell of the cologne of the perpetrator may be triggering.
  • If traumatized by a tornado, seeing a news report with a tornado prediction may be triggering.

In other words, the triggers that can cause a PTSD flashback can be anything that the person finds relevant to the trauma he or she experienced.

Identifying Triggers that Cause PTSD Flashbacks

It’s important to become aware of your PTSD triggers in order to start preventing future PTSD flashbacks. Once you know what they are, you can learn how to deal with them or avoid them.

For more on preventing PTSD flashbacks, see here: How to Stop PTSD Flashbacks?

article references

APA Reference
Tracy, N. (2021, December 23). Why Do Flashbacks Happen? Causes of a PTSD Flashback, HealthyPlace. Retrieved on 2024, July 22 from

Last Updated: February 1, 2022

Medically reviewed by Harry Croft, MD

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