Did you go on vacation this year? It feels like many of us are spending more time at work than ever before, despite living in an era of unprecedented wealth. With increasingly demanding schedules, many professionals choose to skip vacations altogether. In fact, more than half of all Americans haven't gone on holidays in the past year. At all.

But research suggests that all work and no play could be bad for your health in myriad ways - some more sneaky than others. We generally recognise that leisure is linked to better wellbeing, but what exactly does that mean?

For starters, if you don't take a break every year, prolonged exposure to stress could lead to heart problems. A 2012 systematic review of the relationship between long working hours and coronary heart disease revealed that people who work more than the 8-hour average day have about a 40 percent higher risk of heart disease. It's only a correlation, but researchers speculate that there could be a causal link due to factors such as stress, lack of rest, and insufficient sleep.

Another example is the Framingham Heart Study, the largest long-term observational study that has been investigating cardiovascular disease risk factors over three generations, since 1948. Some of the results revealed that men who'd skip on having a vacation for several years in a row were 30 percent more likely to have a heart attack.

It's clear that your heart definitely needs holidays - but so does the mind. These days it's not uncommon to bring your laptop and try to 'squeeze in a bit of work' even while on break, but you really should try to avoid it. Cognitive science research has shown that people are actually more creative if they let their minds wander a bit, while long hours of toiling at a desk can actually make you less sharp, particularly at an older age. Spending some time away from the workplace is therefore likely to make you more productive once you're back.

Lying on a beach or (carefully) taking selfies at historical sites also has mental health benefits. Apart from the obvious and immediate boost in one's mood and life satisfaction, vacationing could also decrease depression. A trend in observational studies shows that people who take more vacations are less prone to have depressive episodes - and all of this probably comes back to the reduction of stress a holiday can provide.

The good feelings of a vacation are indisputable, as Dutch psychologist Jessica de Bloom found while conducting an international study. "People felt healthier during vacation. They had a better mood," de Bloom told Brenda Wilson at NPR. "They were less tense. And they had a higher level of energy, and they were more satisfied with their life."

So how does this account for the dreaded post-vacation blues you get when your email inbox is way too full and the office microwave smells like fish all over again? Well, it doesn't. De Bloom found the positive impact on one's mood dissipates quickly after getting back to work. However, the health benefits are still there, so mood fluctuations alone don't show the whole point of vacations. "It would be a bit like asking, 'Why do we sleep despite the fact that we get tired again?'" she says.

So perhaps it's time to check your leave balance and spend some nice quality time not working. Tell your boss it's for health reasons.