Unfortunately, it’s not uncommon for people to find themselves midway through their 20s, buried in debt, and not quite sure how they got there. According to Sallie Mae, college seniors graduate with an average of $4,100 in credit card debt—a 41% increase from just four years ago. And yes, sometimes it’s the result of one big unforeseen expense. But most of the time, while it might seem like it piled up overnight, it didn’t—debt is usually the result of small decisions made over time.

Being in debt can feel overwhelming, but it’s not an impossible situation to get out of. The first step, though, is understanding how you got there in the first place. Whether you’re hoping to pay off your credit cards or trying to stay out of debt altogether, take a closer look at the four most common reasons we end up in the red.

1. Collecting Credit Cards

I’m sure you’ve seen the credit card offers—the kind that give you a free round trip ticket or 50,000 points if you spend $3,000 in the first three months or so. Sounds like a good deal, right? It is—for the credit card companies. Most people spend away, thinking they’ll pay the balance off soon, when that “soon” is generally a lot further away than they think. A national survey in 2009 found that 46% of adults age 18-29 had carried a balance in the past 12 months, and 29% had paid only the minimum payment at some point in the last year.

And that’s why creditors make these deals—because they know that most people don’t have the discipline (or the funds) to pay off their balance in full after they rack up the charges. That balance stays put, and those “perks” end up costing you big time.

2. Not Having Enough Savings

Having a solid savings cushion is crucial in order to cope with unforeseen expenses. Experts recommend saving 10% of your gross income, and having at least six months of living expenses put away. But many people don’t prioritize setting money aside. Yes, it’s tough when money is tight, and it’s tempting to forego saving in favor of paying for what you need or want now.

But unfortunately, not having an emergency fund can send you into a downward spiral. When you’re slapped with a big expense—medical bills, car repairs, a last-minute plane ticket—and you don’t have the cash to pay for it, you’ll be forced to put it on a credit card, where it will accrue interest charges and costs much more than it would in the first place.

3. Keeping Up With the Jones'

Sometimes it’s even difficult for me to keep up with the latest trend in technology—new “must-have” products are coming out more frequently than ever before. What’s the difference between an iPad1 and an iPad2—and why would someone need both? I have no idea. Except for that we’re told that we need them, and we’re trying to keep up with our friends and their iPhone 4s (or cars or handbags or vacations or whatevers). And thus we spend money on things that we don’t necessarily even need.

4. Failing to Budget

All of the above reasons really boil down to one: People get into debt because they spend more than they make. Sounds simple, but most of us don’t take the time to really track our income and expenses. And no, sitting down with an Excel document every week doesn’t sound thrilling, but having a budget, and sticking to it, is essential in knowing how much you really have to spend, and not going over your limits.

The temptations to spend and the realities of our finances look a little different for each of us. But once you’re able to pinpoint the reasons you personally get into trouble, you can take precautionary steps to make sure you don’t follow the same path again (or never get into debt in the first place).

How, exactly? Stay tuned for our upcoming articles on debt management—what to do if you find yourself in it, and how to start taking smart steps to get out.

Photo courtesy of Stephanie Wesolowski.