Answer: A foreclosure would be a major black mark on the couple’s credit reports and probably would reduce their scores to subprime territory (below 620). Recovering from such credit blows is tougher than it was a few years ago, when lenders were still eager to give money to people with shaky credit.

That means your son and his wife could spend several years in credit limbo. They may have trouble renting an apartment, be required to make bigger deposits for utilities and phone service and even (in some states) pay more for insurance. Whether their credit will recover before home prices do, though, is an open question. Typically, negative marks like a foreclosure fall off credit reports after seven years, and credit scores can recover to near-prime levels before that.

A foreclosure also puts borrowers in a kind of penalty box with lenders. They may not be able to get another mortgage for four to five years. If they were to arrange a “short sale” or voluntarily hand over the keys to the bank, rather than waiting for a formal foreclosure, their “penalty box” period could be as short as two years, although they would still suffer significant damage to their scores.

If the couple are having trouble making their mortgage payment, they should contact a housing counselor approved by the Department of Housing and Urban Development (referrals at http://www.hud.gov to review their options and see whether they should try to pursue a mortgage modification to make their payments more affordable. Relatively few homeowners succeed in getting permanent modifications, but it’s certainly worth a try before they walk away.

They should also read attorney Stephen Elias’ book “The Foreclosure Survival Guide” to understand what may lie ahead.

Answer: A payment that’s 30% of your income isn’t ideal, but it’s not what’s causing your financial problems. Most likely overspending in other areas such as a too-expensive car loan or credit card debt is where the problem lies.

But you do face a significant risk of your payment rising to unaffordable levels when interest rates finally start marching up again.

Your first step should be contacting a HUD-approved housing counselor to discuss your options, including the new enhancements to the federal Making Home Affordable Program. You can get a referral at http://www.hud.gov. (Many housing counselors work at credit counseling agencies that can also help you work out your budget issues.)

If you can’t get a loan modification or refinance, you can consider a short sale, in which, with the lender’s approval, you sell your house for less than what’s owed and the lender accepts the proceeds as settlement of your loan. Short sales will hurt your credit, but you’ll be able to buy another home sooner than if you simply walk away or let your home go into foreclosure.

Answer: Contact a housing counselor approved by the U.S. Department of Housing and Urban Development. You can find links at www.hud.gov. This free counselor can review your situation and help you deal with your bank.

You may need to face the possibility that a loan modification may not help. Sometimes to create an affordable payment, lenders would have to reduce the amount you owe, which few are willing to do. Even if you do get a payment you can afford, you probably will owe more than your house is worth for many, many years to come.

To help you sort through these issues, read the Nolo book “The Foreclosure Survival Guide: Keep Your House or Walk Away With Money in Your Pocket” by attorney Stephen Elias.