I would say that disorder is what it becomes when that emotional dysregulation starts to interfere with getting through our day to day, or when it starts to harm those around us etc.

I had no real trauma as a young child but found myself in one traumatic situation or another as I entered my teen years.

My psych had said that some people are hypersensitive to their surroundings and what others brush off as simple slights or minor nothings, some people internalize far more deeply and are far more affected and that THAT brings out a more pronounced emotional response. so kind of a 'what came first, the chicken or the egg' were we traumatized at a young age? Or do we perceive trauma more easily (and of course some ARE definitely victims of actual trauma)