It's the middle of summer, and whether you're off on a two-week European getaway or a quick weekend in the mountains, good for you. You deserve a break from work. According to a recent study, 40 percent of people don't use all their vacation days each year. And 80 percent of working Americans are stressed out at work and in desperate need of a break.

But don't check yourself out of work quite yet. Your vacation is the perfect time to gauge how your career is going. In fact, taking a vacation might just be the most important thing you do this season -- it will help you get a bird's-eye view of what is really going on and what to do when you get back to the office.

Here are four questions to ask yourself while on vacation:

How burned out are you?

It's your first night of vacation. Are you collapsing from exhaustion and thinking only of the hours of sleep you'll finally be able to clock in? Or, rather, do you feel energized and ready for the relaxing and fun days ahead?

This question not only gauges how badly you need a break -- it also sheds light on your regular work pace. Does your job keep you going at a manageable, steady pace, or are you stuck in a cycle of crash and burn? Take time to reflect on the sustainability of your work schedule and demands. Take out a pad of paper and write out some concrete changes you can implement so you can maximize your energy and avoid burnout.

How plugged in are you?

You're sitting by the pool and enjoying the sunshine. How often do you find yourself checking your phone for work emails and updates? How many times do you call in to the office even though you officially took the day off? And most important: how do you feel when you do it?

Being plugged in at work is either a really good sign or a really bad sign -- that's why that last question is so important. Think about why you feel the need to check in with your co-workers: do you do it because you are excited about the developments on your latest project? Or do you stay plugged in out of fear that your vacation is only putting you even more behind and at a disadvantage in a shark tank workplace?

If you're plugged in out of true enthusiasm and curiosity, great! You have a healthy relationship with your work. If you're plugged in out of anxiety, then it might be time to reevaluate your relationship with your work, your co-workers, and the office culture. Is it truly a good fit? What would ease the anxiety? Is it time to leave?

Are you running wild with ideas?

You're sightseeing and taking in the wonderful, energetic city around you. And suddenly, into your head pops the perfect solution to the work problem you've been having for months. By the end of your vacation, you have tons of ideas to make your latest project even better. Does this sound like you?

If yes, then congratulations. This is a clear sign you are in the right job and operating in your zone of genius. You are not just running through the motions with your work --you are a key, innovative member of your team.

If you're not running wild with ideas on vacation, when do you come up with brilliant ideas? Do you ever? If no, it might be time to rethink your job fit or consider ways to jumpstart your true hunger for great work.

How excited are you to get back to work?

You're packing up to head back home. Are you happy to think about the next morning when you'll be walking back into work? Or are you silently screaming in your head that you don't want to go back, that you want just one more day of vacation?

Here's the thing: we live in a society that labels work and vacation as total opposites. But that is not true -- it is absolutely possible to both love your work and revel in your time off. If you're on the brink of throwing a fit at the thought of going back to work, then it's time to make a plan to shift into your dream job (yes, your dream job is possible!). You don't want to just survive at work, you want to thrive and find fulfillment in your career. Let's make that a priority.