NEW YORK (MONEY Magazine) - As the real estate boom inflated home values all over the country, millions of would-be owners did whatever it took to join the party: bid well over the asking price, hit up parents for a down payment and resorted to ever more creative financing tools, from short-term adjustable-rate mortgages to exotic interest-only option-payment loans.

Now that the party seems to be winding down, many of those borrowers are going to be left with a messy cleanup.

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As many as 3 million homeowners holding more than a trillion dollars in adjustable-rate debt will face an interest-rate adjustment in the next two years, according to the Mortgage Bankers Association.

Assume that adjustment will be in one direction: up.

If you shaved your monthly payments by putting off paying principal, your day of reckoning will be that much more intense. Mortgage rates are at their highest in four years, and with rates on ARMs nearing those on fixed loans, you won't find any easy or cheap solutions.

"There are going to be people getting into trouble," says Christopher Cagan, the director of research at data provider First American Solutions. He's found that nearly half of borrowers who took out ARMs in the past year have 10 percent or less equity in their home, making it hard for them to refinance easily or sell at a profit, especially if prices in their local market have softened.

If you are nervous about what your mortgage payments might look like next year or next month -- or have already seen them increase by hundreds -- now's the time to do some serious calculations. The decision about whether to refinance is complex -- you must factor in your budget, how long you plan to stay in your home, your tolerance for risk and what fees you might pay to get a new loan.

The three families you are about to meet are grappling with these issues. Read on to find out how our experts suggest they survive the rate hikes coming their way.

• Toni Lapp: This single mom should hope for a rate turnaround. Risk: 53% increase in monthly payments.
• Aaron and Lacey Blank: Young first-time buyers need to build equity. Risk: 81% increase in monthly payments.
• John and Mona Ramonetti: These risk-takers should refinance to a fixed loan. Risk: 68% increase in monthly payments.