How exactly can a work friend do all that? For one thing, you’ll feel more relaxed and comfortable at your job. “Three-out-of-four workers recently told CareerBuilder.com they suffer from work stress,” says Lorenz. “Having a friend on the job can help ease those pressures.”

And sometimes it’s almost as if you were meant to become friends, whether you met through work or another way. Sigrid Rapp, 29, met one of her best friends when they traveled together for work. “We had the opportunity—because our flight was so incredibly delayed—to talk for hours and get to know each other, and really just found that we had a lot in common,” she says. “So, since then—about three years ago—we talk every day and she is my total confidant!”

Why work friends can hurt.
Let’s say one of you moves up, can you still be friends? Or worse, what if your friend becomes your boss?

“If you’re both vying for the same promotion, it could cause some tension in your personal relationship,” says Lorenz. “A change in your buddy's rank can put a strain on the friendship, especially if you report directly to your friend.”