A painful memory: an intensely vivid memory of a traumatic experience that returns repeatedly
Flashbacks are considered one of the re-experiencing symptoms of PTSD. The re-emergence of a traumatic memory as a vivid recollection of sounds, images, and sensations associated with the trauma. The person having the flashback typically feels as if they are reliving the event.
A flashback can vary in severity. A flashback may be a temporary occurrence, and a person may maintain some connection with the present moment. On the other hand, during a flashback, a person may lose all awareness of what is going on around them, being taken completely back to their traumatic event. Similar to a dissociative episode, during a flashback, a person may also lose track of time.