When burnout was named an official medical condition in May by the World Health Organization, it raised a lot of eyebrows and legitimized the feelings of millions that feel that Sunday night dread.

On October 3, the website theinterviewguys.com (a job interviewing advice portal) published a study on their site among 928 employees using the Maslach Burnout Inventory (MBI) questionnaire. Each respondent received a score of 1 to 100 after answering the questions; higher scores meant a greater likelihood of experiencing burnout. 50 is the median score, anything above that means an increasingly greater chance of experiencing burnout. The study also measured those reporting burnout related symptoms in the past year (what percentage suffered which symptom) and the associated burnout score.

What follows are the top eight most commonly cited burnout symptoms (with the percent experiencing them). Note that for any symptom, the associated burnout scores (while not listed below) ranged from the 50's to high 60's, all above average for triggering burnout. In other words, if any of these symptoms describe you, you're more likely than the average person to experience burnout.

1. Customers, co-workers, or clients irritate you. (71 percent)

I'd argue that all three are simply the cost of being in business, but it's co-workers grating on you that makes your job not so great.

When it comes to irritating co-workers, it's important to remember that you shouldn't try to fix them, just the interchange with them. Take the initiative, stop making assumptions about their intent behind the behavior that irritates you, and build small bridges or little ways to connect with them, slowly building up from there.

2. You're sleeping poorly. (55.9 percent)

This is about poor sleep caused by worrying about work right before going to bed. To avoid this, do whatever you can to avoid bringing home work and stop imagining each night what could go wrong tomorrow, instead picturing what will go right. For me, continued poor sleep was the ultimate indicator it was time for me to leave corporate behind.

3. You lack motivation to go to work. (54.3 percent)

There's no bigger de-motivator than if your work lacks meaning. To infuse it with more meaning, recommit to learning and growing on the job, ask for more autonomy, find the sense of purpose in your work, and leverage each day at work to live your most closely held, non-negotiable values.

4. You lack energy to be consistently productive. (53.9 percent)

The lack of energy may be related to all three of the prior symptoms. The bottom line is sustained low-levels of energy doesn't bode well for your performance or happiness. Ask yourself what saps your energy and find ways to do less of it, and what zaps you with energy and do more of it. If you can't muster the energy in your current job, it may be time to put energy into finding another one.

5. You feel cynical about your job or company. (47.9 percent)

Cynicism is the worst of the ism's, far worse than pessimism and the opposite of optimism. The truth is, cynics get their power when no one challenges them. Odds are a lot of your cynicism feeds on itself not only when you share it with like-minded others but also via silent stewing about how your job or the company makes you feel. Left unchecked, it's hard to overcome.

6. You have difficulty concentrating. (45.7 percent)

When you're doing something you love, you're in a state of "flow", as famed psychologist Mihaly Csikszentmihalyi calls it; i.e. you're in a highly focused yet relaxed mental state of super-productivity, lost in the enjoyment of the task and not aware of time going by. When you're feeling burned out, it's the opposite. You often can barely concentrate because you're too tired, frustrated, or uninterested.   

7. You lack a sense of satisfaction with your achievements. (40.6 percent)

When you no longer feel good about what you've done well (and should feel good about), it's a major warning sign. We're wired for achievement but if what you're achieving truly doesn't matter to you, that's another matter altogether.

8. You feel disillusioned about your job. (29.5 percent)

Interestingly, this symptom had the highest associated burnout score; i.e. those that answered feeling disillusioned had a burnout score of 67, off the charts on the MBI as an indicator for burnout. If you're disillusioned, than you don't believe in what you're doing. Have you ever done anything well that you didn't believe in? Poison.

The bottom line is if you're ringing up these symptoms, it may be time to ring up another employer for an interview.