The most familiar type of post-traumatic stress (PTS) — the one that gets most of the press — is caused by an acute stressor, a life-threatening event that exerts an extreme reaction in the central nervous system (CNS). Examples are military combat, rape, mugging, a gun held to your head, a serious car crash — anything life-threatening.
Another type of post-traumatic stress is caused by less intense but longer-lasting stressors, often suffered by people who are sued, put on trial for crimes, investigated by the IRS, persecuted, discriminated against, or ridiculed at work or school. It doesn’t evoke significant fear of harm or annihilation. Instead, it brings a terrible dread of shame, humiliation, isolation or loss of status and resources, if not personal freedom. It keeps the CNS at a chronic level of heightened stress. Intimate betrayal typically evokes this kind of PTS response.
A Physiological Model
Suppose there are four columns holding up the ceiling of the room you’re in right now. No one else is in the room. Suddenly the column near the door and window buckles, blocking your path of escape. If it falls, the ceiling will collapse. The only way to save yourself is to prop up the column with your shoulder, until help arrives. About 24 hours later, help comes to secure the column and prop up the ceiling, safely relieving you of the burden.
When you try to walk away, you’re unable to straighten up and walk normally. The over-exerted nerve endings in your shoulder, side, and leg muscles have paralyzed the tissue around them, temporarily rendering key muscles nearly immobile. The condition gradually eases. Within about three days, you can finally stand up straight and enjoy full mobility. But for another three days or so you would experience occasional muscle spasms in your shoulder, side, and legs, where most of the stress was concentrated. These are rough estimates of recovery time that do not allow for variations in age, health, muscle tone, flexibility, etc. But you get the idea. There is a prolonged recovery process from prolonged stress.
A similar condition occurs with emotional stressors that go on for a long time, such as walking on eggshells in your home, living with continual criticism or contempt, or suspicions of deceit, infidelity, or embezzlement by an intimate partner. Once the stressor has finally passed — the betrayal is exposed and the subsequent free-fall condition has abated — the CNS does not return to normal for quite some time. (Precisely how long depends on the duration of the stressful conditions and the determination to focus on healing, repairing, and improving.) Instead of localized spasms of nerves and muscles trying to return to normal functioning, the entire CNS must re-calibrate to find a normal range of arousal, without the chronic stressor “pressing” against it.
The mental equivalent of muscle spasms during the CNS re-calibration process is experienced as waves of negative emotion, which seem to come out of nowhere. Often with no discernible trigger, waves of emotion seize control of your body — which becomes tense, rigid, and agitated. They dominate your consciousness and make it seem like you’re incapable of thinking about anything other than how terrible you feel or how awful your partner is for making you feel so bad. They typically start with a flash point — an abrupt awareness that you’re about to experience something horrid. A physical marker sometimes occurs with the flash point, something like a pit in your stomach, a sharp pain, muscular weakness, or blurred vision. SOURCE