As a career coach working with young professionals, I've known all too well that burnout is a serious issue impacting employee engagement and productivity. It wasn't until this year, however, that the World Health Organization (WHO) recognized burnout as a workplace syndrome and included it as an "occupational phenomenon" in the International Classification of Diseases (ICD-11). The decision validates the experience of many employees, especially Millennials and especially women, and acknowledges the urgency to address the unsustainability of a work culture that reinforces unreasonable hours at work with no rest or sleep, and boasting about it as some kind of achievement.

That burnout is an issue in the United States comes as no surprise considering it is the only advanced nation that doesn't guarantee paid time off, and of those who enjoy the perk, over 50 percent don't use all of it. What's more worrisome are the reasons for the aversion to taking time off: increased feelings of stress and guilt while on vacation, scrutiny from colleagues or managers, inability to unplug, and fear of losing one's job. The cult of being busy as the only road to success seems cool in a Cadillac commercial, but when you consider the negative impact of such a lifestyle, you understand that burnout is a high price -- and unnecessary one -- to pay.

Any employee, whether you work in government, the private sector or the startup or nonprofit worlds, is susceptible to burnout. Burnout, as defined by WHO, results "from chronic workplace stress that has not been successfully managed." The top five reasons people experience burnout are unfair treatment at work, unreasonable workload, poor management, lack of a clear connection between the employee's role and a larger purpose, and time pressures. Though increased focus on what managers and organizations can do to reduce burnout among employees is a step in the right direction, there's a long way to a meaningful systemic change. So if you've recently entered the workforce or are about to, know the signs of burnout and what to do should you start experiencing them.

Following are some signs that indicate burnout.

1. Mental and Physical Exhaustion

This is not about being tired after a long day at work; it's about feeling complete energy depletion all the time. You are so drained that you either can't sleep or when you do, it's not the sleep that recharges and reenergizes you. Instead of getting up excited for the day, you wake up with a sense of dread. Such exhaustion affects your performance at work, and it also increases your anxiety at the prospect of doing mundane activities like grocery shopping.

If family and friends start making remarks about you spending too much time at work, talking about work all the time, and/or complaining about being too tired to hang out with them -- or if they make comments about a change in your mood, attitude or behavior, don't dismiss them. You know yourself best, but it's those closest to you who may notice something's amiss. Pay attention to what they say. It takes time to burn out and you can ignore the warnings for only so long. Don't wait until it's too late.

2. Negativity and Cynicism

Another sign of burnout is a change in your attitude toward work. That's especially the case if you started as an engaged employee ready to dive into initiatives and projects and eager to tackle with creativity any issue. If you now find yourself welcoming new proposals with negativity and cynicism, figuring out how to avoid projects instead of joining them; feeling demotivated and unexcited about activities you previously loved; or no longer seeing the meaning or purpose of what you do, you are experiencing burnout. In fact, burnout has been shown to have the most impact on high performers, so if you are one, be more vigilant.

3. Decreased Productivity

Although it may feel as if you are working harder and longer, at the end of each workday, you rarely feel accomplished. Your to-do list keeps growing and more projects are left incomplete. Since high-performing employees are most at risk for burnout, as they begin to experience symptoms, they may try to do more, which causes further issues. When you are no longer bringing your best self to work, can no longer stay focused, and can't distinguish priorities from everyday tasks, it's time to admit you are burned out and that you should do something about it.

What Can You Do About Burnout?

You must first recognize that you can't handle chronic work-related stress. No person can. Out of shame or fear, many refuse to admit their burnout until it's too late, and when burnout is not addressed, employees face serious health problems, including heart issues, insomnia, depression, gastrointestinal issues or panic attacks. Acknowledging you are burned out doesn't mean you admit weakness or inability to tackle the demands of work. That is the attitude that burned you out in the first place! Next, know that recovering from burnout will take more than going on vacation or deciding to leave work earlier. That said, you can take certain steps to begin the process toward a healthier work lifestyle.

Step 1: Identify What's Causing the Burnout

What about your work environment has negatively influenced your attitude and engagement level? Your manager? Your colleagues? Unclear or unreasonable performance expectations? New responsibilities with no compensation? No opportunity for growth? Boredom? Frustrating processes? Losing sight of the big picture? Identifying the reason(s) for burnout helps you craft an appropriate strategy to tackle it.

Step 2: Focus on What's Meaningful

As you clarify which aspects of your job create discontent, be sure to also acknowledge the ones that give meaning to your experience and keep you in the role. Those are the ones you may need to focus on as you move forward and discuss options for re-engaging. If you can't find anything meaningful, you may be in a toxic work environment and need to consider a career change.

Step 3: Talk to Your Manager

Employee turnover is costly to employers, and addressing burnout is integral to your well-being and the employer's bottom-line. When you know what keeps you engaged and what causes you to burn out, sit down with your manager (or other higher-ups) and discuss options to address the discontent. Be your own advocate and point out the value you bring as well as what keeps you engaged. Offer your ideas on what could change but also solicit feedback from your manager.

Step 4: Develop A Self-Care Routine

Whether you stay with your current employer or not, developing a solid self-care routine will benefit you in the long run of your professional career so that you don't risk burning out in the future. You can consider exercise, more time outside, unplugging for a few minutes each day, increasing social activities or me-time (depending on your preferences). Most of all, please take your vacation and truly relax; it will increase your productivity. If you can't afford an extended trip, try "micro-cations," which are the shorter vacations becoming popular among Americans. And if your employer offers it as an option, why not consider a sabbatical? It may be just what you need to re-evaluate your goals and values.