They say that, with age tends to come experience, and in the workplace, that can be a valuable thing. Yet a growing number of employees are coming to find that their age works against them, not for them, when it comes to career advancement.

According to AARP, an estimated 67% of workers aged 45 to 74 claim they've either seen or experienced age discrimination on the job. Furthermore, job searchers over 35 feel that age discrimination is a major barrier to getting hired. And they're probably not wrong. Following the 2008-2009 recession, workers 55 and over who lost their jobs were unemployed for 40.6 weeks, on average, compared to just 31.6 weeks for younger job seekers.

Older businessman working at a computer.

IMAGE SOURCE: GETTY IMAGES.

If you're an older worker, unfortunately, there's a strong chance that, at some point or another during your career, your age is going to become more of a liability than an asset. That's why it's critical to fight back against age discrimination rather than accept it, or take it lying down.

What is age discrimination?

Age discrimination is the act of treating employees less favorably due to their age. And it's very much illegal.

Denying an employee a promotion because of his or her age is against the law, as is making negative comments about a worker's age. That's why the Age Discrimination in Employment Act (ADEA) was put in place to protect workers 40 and over.

The ADEA applies to private companies with 20 or more employees, as well as state and local governments, employment agencies, labor organizations, and yes, the federal government. Under the law, older workers can't be treated unfairly because of their age, which means they can't be laid off or relegated to lower positions on the basis of age alone. Age-related harassment is also prohibited -- though, as a general practice, workplace harassment across the board typically isn't condoned.

Fighting back against age discrimination

If you feel you've been the victim of age discrimination, you can, and should, take steps to protect your rights. Your first course of action should be to file a complaint with your human resources department, assuming your company has one. Many large employers have internal policies in place to protect workers from discrimination of any sort, so it pays to document any incidents you encounter and bring them up to the right person within your company.

If that doesn't resolve the issue, your next best bet may be to file a complaint with the Equal Employment Opportunity Commission (EEOC). Age discrimination claims account for more than 20% of the charges received by the EEOC, so if you go this route, you won't be alone. Another option is to hire an attorney to file a lawsuit against your employer -- that is, if you're willing and able to spend the money.

Another way to protect yourself is to read up on age discrimination and know your rights. For example, it's actually legal for current and prospective employers to want to know your age, as well as the year you graduated college. On the other hand, it's not legal for them to use that information against you.

Finally, if your company is known to treat older workers unfairly, you may want to jump ship and find a new role rather than subject yourself to a potentially toxic environment. While that may seem like running away from the problem, you'll probably be happier working for a company that respects employees more in the first place -- regardless of how old you happen to be.