PTSD and PTG can both arise from psychological struggle with a highly stressful or traumatic event. PTSD is a diagnosis marked by the experience of multiple trauma-related symptoms, to include re-experiencing the trauma (intrusive thoughts, memories, flashbacks, or nightmares), avoidance behaviors (avoiding people and situations that remind us of trauma), cognitive distortions (loss of memory, counterproductive ideas about life and what happened, persistent negative mood), and increased arousal (irritability, aggressive behavior, hypervigilance, startling easily, sleep problems).
Posttraumatic growth is a process whereby we transform our struggle into a new path, and an outcome where we experience positive changes because of the struggle in the aftermath of trauma. Some people experience symptoms of PTSD and posttraumatic growth at the same time.