Very hard to explain. Its a wave of what feels as dysfunctional ion channels or cellular, feels horrible, in the whole body, unable to stand, turn pale, unable to do anythying whilst it lasts. Its not as if you are fainting, uncomfortable sensation in the body, not muscle, not bones, not organs...can't quite explain. I suffer no panic attacks, no depression and take no meds. I have not had this symptom for a few years, then, suddenly, it reappeared, along with other symptoms. Many thanks for your input.