NEW YORK (MainStreet) – Over half of Americans leave vacation days on the table each year, with an average of nine days going unused in 2012. Many workers say it's because they can't afford to travel. But that all depends on how you look at it.

Think of it this way. Chronic stress leads to illness, from diabetes to asthma to heart disease. American businesses spend $344 billion a year on stress-related health care costs, according to a study by Middle Tennessee State University.

Rather than feeling guilt about getting away for a few days, realize that you're investing in your well-being. And that can mean big savings in the long run.

Travel prices drop between the busy summer and holiday seasons, meaning fall is the perfect time to take a last-minute trip. If you need some inspiration, here are our top picks for travel destinations this fall.

Ireland
Prices to Ireland are always cheaper in the fall, in part because the weather can be unpredictable. But if your plan is to stay inside and drink Guinness anyway, then you might as well go when the price is right.

Hawaii

The weather in Hawaii is almost always gorgeous, so it's hard to go at the wrong time. Tourism slows down in the fall, which means cheaper prices and fewer crowds.

The Galapagos Islands

The Galapagos Islands are a dream destination for many, but it's often thought of as unaffordable. Wildlife is active in the fall, but cooler water temperatures make it the off-season with unbeatable deals.

China

According to Fly.com's fare calendar, round-trip airfare from many US cities to Shanghai or Beijing is currently on sale for $600 to $800. For International airfare in general, that is a serious steal.

Cruise the Caribbean

If your idea of stress-relief is an all-inclusive cruise, you can find rock-bottom prices to many Caribbean destinations in the fall.

Staycation

Even if you can't head out of town right now, you should still take your vacation days and do something fun. Check out TravelZoo's local deals section to create your very own stress-reducing staycation.

--Written by Lauren Lyons Cole for MainStreet