Everyone knows health insurance is important, right? It's obvious: If you don't have health insurance because you can't afford it, you know you are risking racking up serious long-term medical bills should you become ill.

But this series is about ways you can harm your financial future when you may not even realize it. For this series, the health insurance warning is really about choosing the wrong plan.

The truth is that every plan is different. Some plans allow you to choose your doctor, others don't. Some have great prescription drug coverage, others limit your options quite severely. If you get seriously ill, you may have to fight with your insurance company to get the treatment you want from the best doctor around. If you violate the provisions of your plan -- say by seeing a specialist that isn't in your HMO -- you may have to foot the bill.

I realized how important the details of your health insurance plan after I had two hospital stays in the same 12 months (but not the same calendar year). I had a C-section and then, eight months later, my gallbladder removed. My insurance covers only 90% of hospital stays up to a certain cap. That 10% in my case meant more than $2,000 of extra bills I hadn't expected.

Don't miss the rest of our series on 15 Ways to Ruin Your Financial Future!

Personal finance expert Dan Solin explains more in this post about the different types of insurance and why it is important to pay attention to the fine print -- not just the co-pay and the monthly premium -- when choosing a plan.

When you're young and virile, health insurance can seem unimportant. Choose unwisely, though, and you can spend a lifetime paying for your mistake. Too little, and a neck injury can leave you broke for life. And don't forget the risk of buying too much -- that can sap money that could be invested, compounding for decades.

If you're wondering why your expensive salon shampoo works so much better than the generic stuff at the local drugstore, this might be part of the reason...

Dan Ariely, a researcher in behavioral economics at Duke University, published a study on Tuesday suggesting that the "placebo effect" works even better when test subjects believe that their medication is expensive. Working with colleagues at the Massachusetts Institute of Technology (MIT), Ariely conducted a study in which he subjected 82 volunteers to light electric shocks. After the first shock, the volunteers were offered a pill that the researchers described as a "painkiller." Half were told that the pill retailed for $0.10 a dose, and the other half were told that it cost $2.50 a dose.

The results were pretty compelling: 61% of the subjects who were told that the medicine was $0.10 a dose found that it was effective, while 85% of the subjects who were told that the drug was $2.50 a dose found it effective. While other studies (not to mention common sense!) have shown that people value things more highly if they cost more, this study demonstrated a very impressive disparity based on cost. Of course, 82 volunteers constitutes a pretty paltry sample size, and this study should probably be backed up with more extensive analyses, but the conclusions were still impressive, and have wide-reaching consequences for generic medications; in fact, Ariely has questioned whether or not cheaper medications may not be less effective, merely by virtue of their lower price.

Given my wife's explorations into bargain-priced skincare and my own experience with the wonders of Trader Joe's vitamin aisle, I wonder how many people are paying small fortunes for lotions, conditioners, and vitamins that are no more effective than generic brands. Take that, placenta shampoo!

Bruce Watson is a freelance writer, blogger, and all-around cheapskate. He's found that bargain-priced beer gets him just as toasty as the pricy bottled stuff.

If you're having trouble with the high costs at the pharmacy and you're being forced to choose between putting a meat loaf on the table or following doctor's orders, then you need to know that there's a bucket load of options available to you for seeking help to pay for your prescription medications.

You can start out by calling the customer service department of the company which manufactures your medication. If you don't know who makes it, ask your pharmacist for help. When you call the manufacturer, make it clear that you are having trouble paying for your medications. You'll probably be surprised at how quickly they try to help you by referring you to programs or agencies that can help you.

While you're talking to your pharmacist ask them if they can provide any additional options for you. There are programs at the county, state and federal levels which seek to provide assistance with prescription costs and your pharmacist should know about these programs. Don't forget to ask your pharmacist about generic alternatives also.

Even if you're not a member, you might consult with AARP.