As I understand, Bipolar is more about energy levels;fluctuating between mania-high and depression-low. Bpd is more about frequent, uncontrollable mood swings or emotional intensity that last a few hours, Mania and depression can each last for a period of months. I'm sure someone will correct me with a DSM background but I'm speaking from personal experience because I have both. I have more problems with the BPD. Bipolar is more 'friendly' to the general public and psyche scene and can be treated with meds. My Dr. told me there is no medication for BPD. I think it comes from having a traumatic childhood.