It's important not to see someone purely in terms of their diagnosis. People with BPD can have very low self-esteem, and it can help them enormously if you can emphasise the positive parts of their personality. It can be extremely difficult caring for someone with BPD. They may try very hard to control you, because they feel so out of control of themselves. There may be periods when they refuse to talk to you or when they rage at you. This can be very painful and may remind you of times when you felt powerless as a child. You may find that the person panics and perhaps reacts very angrily when you want to leave or to go somewhere. They may beg you to stay, or hurl words of abuse. It can help if you focus on how they are feeling, rather than trying to argue them out of their fears. the best way to cope is by learning about BPD and then you can help your friend who is suffering also

This s a very difficult calling for you. I do agree with staffie about labels. The other advice from staffie is good as well. I will add something to that about your own self care. Your loved one is virtually incapable of setting and respecting boundaries, so you have to do it and enforce them. He/she will try to manipulate you and dominate your time, not out of meanness, but out of desperation. You are the only one that can set the limits and you may be the one tempted to feel like a "meanie." The borderline personality will use guilt and intimidation. Your care of your time and emotional health is essential to you not falling apart in this demanding and draining relationship. What I like to emphasize with people is that whatever their diagnoses, they are still human beings, still have dignity, and still have responsibility for their choices. It is a gesture of respect to hold people accountable and support them in making good choices. If you can have a calming affect on this person, that is also helpful. You are most valuable to him/her if you can avoid getting caught up in the drama that he/she tries so hard to create. Best wishes and prayers.