There are a lot of factors that contribute to an employee's career being killed off, some are obvious reasons while others not so much. The not so obvious reasons are the ones that employees should be wary of if they don't want to kill their career.

According to an article by Dr. Travis Bradberry, co-author of the Emotional Intelligence 2.0 & a President at TalentSmart, a lot of people don't realize that they are doing things that are already killing off their careers. And these things are usually subtle and "decidedly undramatic."

Killing off a career though doesn't necessarily mean losing one's job. As a U.S. News article pointed out before, these things could contribute to an employee not receiving a promotion or a raise.

So what are these things that are killing employees careers? Here are five things that need to be avoided.

The first thing to avoid is that an employee should refrain from over promising. It's easy to be excited and promise a lot to your colleagues, boss or clients. But doing this only create additional pressure on you and can make you look bad. Even if you only under-delivered by a little bit, the fact that you didn't deliver on your promise will make you look bad.

The next thing that employees should avoid is being defensive. People will always find something negative about your work, even if it's already perfect, so don't be defensive when someone gives a negative feedback on your work. This could result in people not giving their feedback at all, feedback that could help you improve and grow.

The third thing that employees should avoid is being complacent and fearing change. With the world changing at a rapid pace, being complacent and not being open to change can mean the difference between an employee being out of a job or an employee being promoted. Change is inevitable, so it's important that you do not be complacent with your skills and knowledge and keep on innovating.

Another thing that employees should avoid is negativity. Being negative at work creates an unpleasant environment for the people who work with you, which could result in them disliking you and not wanting to work with you. And chances are, this could result in you losing your job or being left out.

The last thing that employees should avoid in order not to kill off their careers is playing politics. Companies are usually working hard to create a good working relationship and environment within its employees and doing things, like undermining colleagues, instigating conflict or spreading rumors doesn't necessarily contribute to that. Companies are more than willing to get rid of rotten tomatoes so it won't spread to the good ones.