ABC News' Amy Robach reports:

Millions of Americans, even those in top professions, say they go to work in fear of bosses and colleagues because of adult bullying.

"It was very difficult to walk into the operating room and be calm if you just had somebody take the top of your head off," said one neurosurgeon whom ABC News is not identifying. "It was clearly humiliating. He also threatened us in terms of our jobs on a regular basis."

She said those two years spent being bullied by her boss were "unadulterated misery and hell."

According to a recent survey by the Centers for Disease Control and Prevention, adult bullying affects an estimated 12 million Americans in the workplace - nearly a third more women than men.

Jane Pratt, the editor in chief of "xoJane," said that earlier in her career, she'd suffered for years from intense bullying by her boss.

"One time, I remember being in a conference room with a bunch of other people around and he was yelling at me so fiercely … his face was red and he was yelling at me so much that I started to feel like maybe I was going to faint because it was too much," she said. "I felt like I couldn't breathe. I felt like I was going to faint."

Jill Brooke, author of "The Need to Say No," has studied adult bullying and said it had almost become accepted office behavior.

"It is becoming an epidemic in the workplace because people are responding to their fear of losing their jobs and status quo as a result," Brooke said. "As a result, they consider this behavior survival of the fittest."

The neurosurgeon said her level of anxiety was constant.

"I ate constantly," she said. "I gained a tremendous amount of weight - probably 40 to 50 pounds."

Brooke said bullies respond to resistance, so victims should speak up - and of course build documentation. She said victims should also build consensus with others because when it comes to combating a bully, strength is in numbers.

Pratt said victims should also learn from their mistakes.

"That was a big part of me starting xoJane with Say Media," she said. "I knew that I could hire people and they would be treated in a really, really respectful way. … You have to set the tone. … Nice works. It really does."