Any current physiological or psychological stress adds to the stress of the trauma, as well as any lack of the endorphins or neurotransmitters that support positive moods, my personal experience being low GABA, having come off of depakote after over 20 years, but not being assessed for low GABA (now on Gabapentin) by a new and subcompetant psychiatrist.

On top of that, with hypercupremia and hypervitaminosis B6 and low GABA, I started having flashbacks of traumatic events that had previously not caused flashbacks. Do not only do a wide range of causes for stress at the time of the trauma increase PTSD, and lack of supportive treatment and understanding directly after a trauma increase the chance and severity of PTSD, but increased stresses at various points after the trauma will increase temporarily the severity of the PTSD, and potentially add to it via retraumatization.

While low cortisol acts as a shock absorber, high cortisol from emotional stresses before the trauma make the trauma worse. But physical issues, such as illness or poisoning (such as hypervitaminosis B6 or hypercupremia, which add stress through unusual and painful sensations, and by limiting the amount of toxins able to leave the body via the overworked kidneys) add also to psychological stress, which adds again to physiological stress by increasing cortisol and adrenaline, and preventing the body from doing standard housekeeping in favor of "fight, flight, freeze, or fawn."

People with abuse backgrounds tend to higher cortisol, or might have hypervigilence syndrome, where even tiny stimulations have a much larger and more stressful effect. That constant or sudden higher stress response may give faster reactions in emergencies, but takes a physical toll, and since it usually goes with specific coping strategies as reactions, the reaction to a later event may be the wrong reaction, adding helplessness or frustration to the original trauma and the layers already added to it.

I suspect that there is a critical level where the traumas add in a spiral which leads to panic attacks: when distracting oneself from the trauma by throwing up, curling up in a ball and/or screaming is safer than trying to deal with the problem. Push any harder and an ulcer (my experience), a heart attack or stroke may result. But not being able to deal with the cause of the stress or trauma can be equally deadly, in some cases.