A person with Narcissistic Personality Disorder (NPD) often initially comes across as charming and outgoing, exuding self-confidence. However, the magnetic personality is cast aside and replaced by a self-absorbed individual.  This person is extremely difficult to deal with. NPD is one of the most difficult diagnoses for professionals to treat successfully. If the individual with NPD is a family member, a supervisor at work, or someone for whom you already care deeply, you might prefer to explore ways to survive close proximity. You can choose to make adjustments that facilitate co-existence with Narcissistic Personality Disorder, but it can be a difficult road.
Determine if it’s worth dealing with this person. This person has very little interest in listening to you and has a lack of interest in what your needs are. Narcissists think they know more than others. Therefore, they see their decisions as the only logical answers to problems. Narcissists will expect that you will defer to their decisions. There will probably be power struggles or severe control issues in your relationship.
Avoid confrontation. You won’t convince a person with NPD that they are wrong. Pick your battles and don’t waste effort in tackling an issue that centers on the person’s behaviors, as they are unlikely to change.
Establish goal-oriented interaction. People with NPD like to achieve things and then brag about their achievements. Set goals to meet your needs that provide a source of pride for your narcissist.
Learn what is important to the person. Remember that a narcissistic personality probably won’t understand or respect your emotional statements or gestures. They may actually reject them in a manner that feels callous and hurtful to you.
Suggest talk therapy. The only effective way to treat this disorder head-on is through talk therapy. Psychotherapy can make inroads in reshaping how persons with NPD perceive themselves and their place in the world. Then they can develop more accurate views of their actual abilities. This can assist them to eventually accept themselves and incorporate opinions of others into their thought processes.
Consider the person’s childhood. Narcissistic Personality Disorder (NPD) is typically found in males, beginning in adolescence or early adulthood. Experts have not pinpointed causes but speculation includes certain types of parenting:
Identify if the person thinks they can do no wrong. A narcissistic personality may first appear to have a strong sense of self-esteem, confidence, and ability. In time, this will be revealed to be steeped in self-belief that they can do no wrong and that they have greater value than those around them.
Consider if the person thinks they are the center of his universe. The narcissist will feel that the world revolves around them, and they will do what is takes to keep it that way.,  This might include monopolizing conversations.
Consider if the person is easily angered or verbally abusive. When a narcissist doesn’t receive the special treatment to which they feel entitled, they might become angry or verbally abusive.
Identify if a person is arrogant or boastful. Persons with Narcissistic Personality Disorder will be seen by most as arrogant, boastful, and self-centered. They tend to look down on their inferiors (basically, everyone else), and may tear others down in order to build themselves up. They will manipulate others to get what they want.
Identify a person’s lack of empathy. Perhaps the most challenging issue in dealing with someone who has NPD is that they have no real ability to empathize with others and no desire to learn.
Notice if a person overreacts to criticism. They will not try to meet the needs of others. In fact, they may react in anger to any request for such, as it may be perceived as a criticism. 
Consider if the person has unrealistic expectations. The narcissist will have exaggerated beliefs of self-importance, superiority, achievement, and ability; manipulative behaviors as well as expectations of obedience, admiration, and entitlement; and preoccupation with “fantasies about success, power, brilliance, beauty or the perfect mate.”
Look at the person’s relationships. It is difficult to work or live with someone with Narcissistic Personality Disorder. Persons with NPD tend to have problems in their personal relationships as well as at work and/or school.
Notice if there is drug or alcohol abuse. When life does not run smoothly, a narcissist may have issues with drugs or alcohol. Examine how much the person is drinking alcohol or if he is abusing drugs.
Seek emotional support elsewhere. Accept right now that your emotional needs will not be met by this person. Find a trusted friend or other confidante (a relative, counselor, or priest, for instance) who will provide a listening ear and understanding for those times you need to talk about your frustrations. Have a network of friends to fill the other emotional gaps left in your life.
Educate yourself to improve your quality of life. Every individual is unique, so educate yourself about Narcissistic Personality Disorder but also do your best to learn how your specific person with NPD processes his world. The better you understand that lens, the more you can adapt your approach to him so that you get the results you seek more often than otherwise.
Don’t forego making emotional gestures. You may find that a person with NPD responds well to the non-emotional favors you learn to do. This doesn’t mean, however, that you have to forego making emotional gestures from your own heart.
Seek advice from other resources. You’ve put yourself on the right track by starting to educate yourself about Narcissistic Personality Disorder. There are numerous support groups, books, and other resources with practical advice to help you survive this challenging relationship.
Share ideas with other people. Don’t forget that you aren’t the only person impacted by the narcissistic personality in your life. Share ideas with this person’s friends and co-workers who are trying to maintain a relationship with them.
Monitor his children. If there are children living with this person, make sure they are safe with this parent. Narcissistic parents can often be verbally or emotionally abusive. Take note if the children are lacking certain social skills because of their behaviors.Consider ways you can compensate or re-teach certain social skills so the children don’t become adults with similar behaviors.