People are jerks.

And there’s plenty of evidence to prove it in the very blunt self-help book called “The A—hole Survival Guide,” a scholarly source that teaches fed-up readers how to deal with co-workers, strangers and just about anyone who sucks.

The author, Bob Sutton, a Stanford University professor, became known as “The a—hole guy” after writing “The No A—hole Rule” in 2007, which focused on building civilized workplaces and surviving one that isn’t. Since then, he’s received thousands of emails from Silicon Valley CEOs, pastors, cashiers, doctors and construction workers who have asked him how to actually deal with one. His new book hits shelves September 12.

“An a—hole is someone who leaves you feeling oppressed, demeaned, disrespected or like dirt,” Sutton tells Moneyish. “I use the word a—hole in part because of the emotional response that people have to it, they get angry.”

Bob Sutton’s new self-help book “The A—hole Guide,” hits stores this month.

Dealing with one — or more — a—holes could cause actual psychological harm, Sutton notes. Workplace jerks damage employee mental health — triggering anxiety, depression, sleep problems, high blood pressure and poor relationships with families and partners.

“If you have somebody who is making you feel that way there are four things you can do: Get out, reduce contact with them by creating distance, practice cognitive behavioral therapy by not thinking about it or changing your perceptions rather than the situation, or fight back and bring them down,” Sutton says.

Some are way worse than others, so it’s important to identify what kind of an a–hole you’re dealing with to find the best solution.

There’s the mood-swinging, temporary jerk who perhaps is having a rough day. In this instance, you might just deal with it until they start acting human again.

“It’s often best to just say nothing, or leave the scene,” Sutton writes.

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If it’s a colleague or friend you might typically like, Sutton suggests confronting the bad behavior with candid conversation. Offer support if they’re having an off-day.

Or if they’re really nasty, you can literally be distant. If you’re forced to interact with the temporary a—hole at a work function or event, sit or stand a few extra feet away. Don’t make eye contact and blend into the background. Find a friend or boss to mingle with instead.

When a boss is being a temporary a—hole, however, it can sometimes improve an employee’s performance, Sutton notes. If management spews unexpected venom, the rare outburst could be interpreted as negative feedback and may fire up workers to try harder. In one study, coaches who showed that they weren’t happy with their players performance saw slight improvement in their team before the end of the game. Coaches who were consistent a—holes though — showing intense anger, throwing things, and expressing verbal abuse — actually drove down performance.

In the book, Sutton goes on to identify plenty of high-profile leaders who have achieved vast success without treating people poorly, like Apple CEO Tim Cook, Netflix boss Reed Hastings, celebrity chef Anthony Bourdain and executive producer and writer Shonda Rhimes. And he stresses it’s important not to mistake toughness with being a jerk. Just because a boss has high expectations, demands a lot and isn’t particularly warm, doesn’t mean they’re an a—hole.

Another type of a—hole is a Machiavellian one.

“If you’re nice to them, they take it as a sign of weakness and they start being nasty to you. You probably either need to get out or fight them more openly,” suggests Sutton.

And these types can rub off.

“It turns out that rudeness is like catching a common cold. If you’re around rude behavior you will in turn be rude,” he says.

A 2012 study mentioned in the book showed that abusive leaders were prone to choose or breed other abusive leaders which stifles team members’ creativity. Other damage includes reduced trust, motivation, innovation and less willingness to make suggestions.

So before calling someone an a–hole point blank, it’s important to consider how much more power you have over them. If its a colleague, then it’s easier to frankly or passively tell them off, but if you have less power, the bully can hurt your reputation, and you’re at risk. So Sutton writes that it’s important to recruit a few allies to help protect you before going to the extreme of quitting.

“The less power you have, the easier it is for jerks to get away with hurting you,” says Sutton.

He suggests documenting every incident that way you have solid evidence to prevent the “he said, she said” situation in Human Resources. Keep notes and take pictures and even videos if you can, and encourage fellow targets to do the same.

And, in some out of the office instances, it’s perfectly okay to put someone in their place when they deserve it — whether it’s flipping someone the bird for cutting you off in traffic, or confronting the a—hole who cut the line at Starbucks.

“I’m not the civility police,” Sutton quips.