7 signs you may be dealing with a narcissistic coworker or boss - and how to deal with them

If your coworker is constantly gearing the conversation back to themselves, they might be a narcissist.

"They always want to be surrounded by their 'fans' and love 'holding court,' telling stories while others listen in a state of rapture," Lavender said. "Often these stories center around what they considered to be their 'amazing' accomplishments, usually over exaggerating their achievements."

What to do: Understanding that you can't stop your coworker from these flights of fancy, try to change how you think about them instead.

"Remove the expectation that they are going to behave logically," Borysenko said. "It's not going to happen, and once you detach from that expectation it will help put their behaviors in context."

A narcissist won't accept even the smallest piece of criticism, Borysenko said. Any inkling that they're less than perfect will drive them over the edge.

That makes it impossible to move ahead in the workplace if you need to tell them something they did wrong.

What to do: Lavender suggested "sandwiching" your critiques. Here, you begin with something positive, include your criticism in the most positive way, and then end with another positive message.

Here's one "sandwich," provided by Lavender:

"Frank, I just called you in here to let you know what a fantastic job you're doing for us. Your numbers are sky high! We can really use your talent.

"I wonder if you could help some of the other salesman by being a little more patient with them. They could learn a lot from you. When the secretaries and other coworkers ask you for help, try to understand that they are looking for you to be the leader that we see that you are.

"Could you help us out that way?"

Narcissists are highly manipulative and believe that they are inherently superior, Lavender said. They'll do anything to achieve their of being in charge and are happy to charm the higher ups to get what they want.

And, it actually sort of works, Lavender said. Because narcissists are charming and confident, people (including your bosses) are drawn to their alluring energy.

Your bosses might reward your narcissist coworker with promotions and raises even if he or she didn't do the work. Studies have shown that narcissists are more likely to assume leadership roles — though research has also shown that they're not necessarily more effective leaders.

What to do: If you notice your bosses are rewarding your narcissistic coworker with opportunities that you aren't able to enjoy, it may be time to consider a new job.

A company that promotes people who are ruthless and lack empathy is probably not one you want to be part of.