Others have already alluded to triggers. That seems to the best best telltale sign of incoming BPD dys-regulation and spin-outs. Everyone is different, some people will numb out when they are triggered, others will become increasingly emotional until breaking point; it all depends on how you react to your particular triggers.

I know for myself, my Borderline traits don't ever really, go away. They are always present, though at times they are less prominent - especially when I have taken time to meditate and ground, etc. Stress obviously exacerbates the symptoms, perhaps that is something you can concentrate on as it has an impact on everything else. For myself, physical symptoms are what I notice first: typical fight / flight mode. Once I notice these physical symptoms I know something is wrong and I have to sit with the emotions to determine what is going on inside my head.

Keep in mind that having a flare-up of, "symptoms," isn't necessarily indicative of Borderline issues. We are human and and part of the human condition is to experience emotions. We Borderline sufferers experience emotions more intensely (at least, that is how the "professionals" explain things). Long-lasting symptoms after having experienced a trauma, is a very real and normal response. It simply means that we are human.

I think you have to determine what your triggers are. When things start to get hairy or feel uncomfortable, try to remain aware of them. Practicing mindfulness will allow you to discover what specific triggers you have and what they do to you. Once you have done this I believe you will answer your question by yourself.

Thanks,
HD