PHOENIX -- Homes nationwide are literally rotting from the inside out, and it could be happening here in the Valley.

The problem is defective drywall, and it could be harmful to your health. It's a product in U.S. homes made in China.

"What a nightmare to try to figure out if you do or not," said Southwest Premier home inspector Josh Lutz.

It's a nightmare Lutz hopes he doesn't have to face here, but one that's popping up across the country.

It's causing copper to corrode, producing a stinky, rotten egg smell. Physical problems include sore throats and a headache; dry, burning eyes and respiratory infections.

The culprit is bad drywall. The U.S. Consumer Product Safety Commission said it's coming from China.

It's a problem that's affected thousands of homes, but it's primarily being reported in the Southeast.

But Lutz said that's because the chemical behind the problems, hydrogen sulfide, needs heat and humidity to be activated. So unless you've got a leaky pipe, you might not even know it's there.

CBS 5 wanted to know how to check before it's a big problem.

"So basically all you do is go up in your attic, find a spot that's easily accessible, brush away the insulation," Lutz said.

Then check the label. The goal is to find out who made the drywall. If it's a Chinese manufacturer, you might be in trouble.

One of the companies that's had trouble in another state does build homes in our area. Lennar Homes has replaced drywall in about a dozen Florida houses, but Arizona Division President Alan Jones is confident it isn't a problem in any of the 10 Lennar communities here.

Jones said his company investigates every question that comes in to verify there isn't a problem.

If your home was built between 2001 and 2007, you might want to check the label. If your drywall is tested and found to be bad, you have no choice but to replace it. That comes with about a $10,000 price tag.

If you suspect you've got bad Chinese drywall in your home, call the Chinese Drywall Complaint Center at 866-714-6466 or visit their Web site at chinesedrywallcomplaintcenter.com.