How to determine if somebody close to you has borderline personality disorder?

See a psychiatrist: See a psychiatrist to be accurately diagnosed but in general symptoms include mood swings, emotional lability, destructive behavior, impulsiveness, risky behavior, helpless feelings and more.

Get help: If the person is close to you, you can't know. Here is the wiki definition which clearly states the characteristics. http://en.wikipedia.org/wiki/borderline_personality_disorder if you are feeling that someone close to you has bpd definitely get some help for yourself. If nothing else you need to strengthen your own support system, caring for someone with bpd is emotionally very difficult. Best.

"Oz" Online Support: "welcome to oz" online support communities are available on randi kreger's site, http://www.Bpdcentral.Com kreger is the author of "walking on eggshells." for the latest on bdp & to find a therapist trained in treatment methods known to be effective -esp. "dialectical behavior therapy" (dbt), see behavioral tech resources founded by the founder of dbt, dr. Marsha linehan: http://bit.Ly/zpjvol.

Borderline: The hardest thing to maintain with borderline personality disorder are interpersonal boundaries. Boundary violations often occur with people struggling with this disorder and whoever your relative is, you're going to have to work on those boundary issues first and foremost, most notably in terms of safeguarding against being emotionally invaded or manipulated by that person.