Not every situation requires a confrontation, and getting angry at every single thing she does won't help anything. For example, consider if it's worth getting upset over a minor habit such as ongoing nail biting, an article of clothing that was never returned or something more serious, such as insulting you in the presence of others. You have the power to decide if a situation is serious enough to address, asserts Preston Ni, a trainer in interpersonal effectiveness and professional communication, on "Psychology Today" online, in "Ten Keys to Handling Unreasonable & Difficult People." Therefore, think twice and assess if the issue is a minor occurrence or if you were deeply offended and believe your future interactions will be impacted by her actions.

As opposed to focusing on minor incidents or annoying personal habits, consider having one-on-one time with him to help save the relationship, if it's at all possible. Author and public speaker Deepak Chopra advises on his website to find a moment when you can sit down and have a candid discussion in which you not only talk about what may be bothering you, but also express your desire to make it better. For example, if you had an exchange that led to an argument, start by being honest. "Your friendship means a lot to me, which is why I felt X..." Then, close it out with, "I will be respectful of your feelings, and I hope that you can respect mine." While this can be awkward, it also helps to clear the air and hopefully provides a positive learning experience from which you both can grow.

When dealing with a difficult friend, it may be easy to attack her character. However, redirect that urge and focus on the incident. Ni highlights that communication situations include two parts: the relationship with the person and the issue you are discussing. Therefore, separate the person from the incident to directly address the issue. For example, you notice she seems to be slacking on her responsibilities after agreeing to do something. Suppress the urge to lead with a character attack, such as "You are so irresponsible." Instead, say something like, "I appreciate your willingness to help, but it seems like some things are falling by the wayside."

It is up to you to decide on your tolerance level and how much you want this friend in your life. And, as hard as it may be sometimes, you may need to set boundaries or consequences to free yourself of any long-term anxiety. For instance, you may need to cut down on phone calls, reduce visits to a weekly basis or only meet in the presence of a smaller group of close friends to avoid confrontation. These steps can provide temporary relief. However, Chopra advises that if you know he isn't going to change and if you've examined all sides, you have the information you need to make the right choice of whether the boundaries are enough or you need to end the friendship.