Intrusive memories in post-traumatic stress disorder (PTSD) are a part of re-experiencing trauma. They can take the form of flashbacks, nightmares, and other types of involuntary emotional recall.

Symptoms of intrusion are among the core features of post-traumatic stress disorder (PTSD), a mental health condition that can develop after experiencing trauma. Often referred to collectively as “intrusive memories,” intrusion symptoms cause you to re-experience trauma in a variety of ways.

Unwelcome, involuntary memories are just one example of intrusive memories in PTSD. Some types of intrusive memories may make you feel like you’re back in the moment the trauma happened.

“Intrusive memory” is a broad term that covers different experiences of remembering trauma in PTSD. It includes unwanted, uncontrollable times of recall (typical memories and thoughts) as well as flashbacks and nightmares.

All types of intrusive memories happen involuntarily. They’re usually emotionally charged and distressing because they’re directly linked to the traumatic experience. Intrusive memories can activate your autonomic nervous system, which includes your “flight, fight, or freeze” response.

If this happens, you’ll experience the same physiological reactions linked to a real threat. You might notice an increase in your breathing, heart rate, and blood pressure, for example.

Intrusive memories in PTSD are more than just passing remembrances. They can involve re-experiencing trauma both mentally and physically.

Intrusive memories are a core symptom of PTSD, necessary to receive a diagnosis under the criteria in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR).

According to the DSM-5-TR criteria, a PTSD diagnosis must include at least one intrusive memory symptom, such as:

  • recurrent, distressing remembrances of trauma
  • nightmares
  • dissociative reactions (flashbacks)
  • mental and/or physical distress at reminders of trauma

Due to the broad range of re-experiences in PTSD, the exact prevalence of different intrusive memories isn’t clear. Flashbacks and nightmares are among the most-studied intrusive symptoms.

In a 2018 study involving 166 people with PTSD, 49% of participants experienced pain flashbacks, which involve re-experiencing the pain felt at the time of trauma.

In a 2023 study involving 398 people with PTSD or complex PTSD (CPTSD), about 92% of participants reported nightmares, but nightmares happened more frequently in CPTSD.

“CPTSD” is a clinical term used to describe PTSD with severe, enduring symptoms, CPTSD is typically associated with repeated or prolonged exposure to trauma.

Intrusive memories in PTSD are considered sensory-perceptual events. They’re usually triggered by one or more of your senses:

  • sight
  • sound
  • smell
  • taste
  • touch

According to a 2019 research review, intrusive memories in PTSD tend to be associated with moments of emotional intensity during the traumatic event.

For example, if you’ve been involved in a flood, hearing a rush of water may trigger the same intense fear you felt in the moment floodwaters surrounded you.

Triggers can make intrusive memories feel as if they are happening in the “now.” Something — a trigger — in the current moment can cause you to involuntarily recall a part of the experience.

Some experts believe that these triggers are part of an exaggerated response to potential danger. Because the sound of rushing water, for example, led to overwhelming danger in the past, it creates an extreme reaction in the present.

Flashbacks are a type of intrusive memory, but they’re distinct from typical memories that are intrusive.

Flashbacks in PTSD can be experiences of dissociation, in which you lose your connection to your current thoughts and sense of self. Unlike typical memories, flashbacks can take over your reality, making you feel like you’re truly back in the traumatic moment.

Typical memories that are intrusive in PTSD don’t involve real-time immersion. They can be uncontrollable and can dominate your thoughts, but they don’t change your perception of reality.

Intrusive memories in PTSD can be disruptive and distressing, but there are ways to work through these experiences.

Typical intrusive memories

Typical memories fall under the banner of “thoughts,” your mental flow of ideas that stem from perception, information recall, and many other mental processes.

As with other intrusive thoughts, you may be able to cope with a memory that’s intrusive by:

  • acknowledging that the memory is not within your control and is unwelcome
  • allowing the memory to come and go without fixating on it or trying to analyze it (mindfulness)
  • understanding that the memory will likely return
  • continuing what you were doing when the memory occurred to help push through negative emotions

Nightmares

According to a 2018 review, managing the overall quality of your sleep may help decrease the severity of PTSD nightmares.

Habits that promote quality sleep include:

  • going to bed and waking up at the same time every day
  • getting daily exercise
  • keeping your bedroom cool, dark, and quiet whenever possible
  • avoiding using devices with screens before bed
  • limiting naps throughout the day
  • developing stress reduction strategies

Flashbacks

Managing flashbacks can be challenging. You might not immediately recognize that you’re having a flashback — it can seem very real in the moment.

As soon as you realize a flashback is happening, you can:

  • focus on controlling your breathing
  • remind yourself this is a flashback
  • ground yourself by focusing on your environment, such as by naming the colors of objects you see
  • seek your preferred source of comfort, such as a warm blanket or a loved one’s embrace

For some people, symptoms of PTSD gradually improve over time. For others, managing PTSD and intrusive memories requires professional treatment with psychotherapy, medication, or both.

Cognitive behavioral therapy is a framework regularly used for PTSD treatment. It can involve approaches such as:

  • prolonged exposure therapy
  • cognitive reprocessing
  • trauma-focused cognitive behavioral therapy

All these methods help you work through distressing emotions and thoughts that can lead to PTSD symptoms.

Medications, such as those that improve sleep or reduce anxiety, might also be a part of your treatment plan.

Intrusive memories in PTSD are involuntary, uncontrollable, distressing experiences of remembering trauma. They create a sense of re-experiencing and can come in the form of typical memories, flashbacks, or nightmares.

Also known as symptoms of intrusion, intrusive memories are a core feature of PTSD. To receive a diagnosis under DSM-5-TR criteria, you must experience at least one form of intrusive memory.

Treating PTSD through psychotherapy, medication, or a combination of the two may improve your intrusive symptoms.