These two videos provide a good description of Borderline Personality Disorder (BPD). Remember that not all nine criteria need to be present to warrant a psychiatrist's diagnosis of BPD.
I have a few comments to add. When the vlogger discusses impulsive and self-sabotaging behavior, she mentions the usual suspects, like reckless promiscuity and gambling. Another behavior that is seldom cited, but could also equally qualify, is self-described "video-game addiction." This could involve playing an online video game like World of Warcraft for hours and hours on end (e.g., 18 consecutive hours) at the expense of necessary life activities.
Also, when the vlogger discusses anger, what is mentioned is the extreme exhibition of aggression. That has been documented in diagnosed cases of BPD, but it is not the only form of intense anger that can be felt by someone with BPD. What is also possible is that the person with BPD holds everything inward and refrains from expressing the aggression, but nevertheless feels it on the inside. Anger toward another person can manifest in an extreme withdrawal of affection from that person. This phenomenon still fits the "intense, inappropriate anger" criterion for BPD. It comes with what is called "the quiet version of BPD."
Anyhow, I find these videos helpful and recommend them.
