Rest easy with these tips for mattress shopping

The only thing more exhausting than sleeping on a bad mattress is shopping for a new one. First, you have to withstand mattress salespeople -- almost as much pressure as shopping for a car. Then, you can't really compare choices among stores because manufacturers make proprietary mattress models for each. And finally, there are the frustrating warranties, which don't cover most of the things that go wrong with mattresses.

Mattress shopping will never be dreamy, but you can make it easier. As a reporter, when I struggle to write a story, I go back to the "five W's and an H" taught in journalism school: who, what, where, when, why and how. Those same guideposts can help me write this mattress-shopping article -- and help you choose a mattress.

Who: You, if you wake up stiff or achy. That's a good indication that you need a new mattress. If you find that you always sleep better and feel more refreshed after a night in a hotel, that's another sign.

When: Experts say mattresses wear out about every 10 years. Of course, that can vary based on the quality of your mattress. It can also vary based on the quality of your body! Some experts suggest that people over age 40 replace their mattresses every five to seven years, because we need better support and are more susceptible to pressure on our joints.

Where:Many people default to a chain mattress store or a department store, which tend to carry the most mainstream mattress brands -- most of which seem to begin with an S. But these days there are other options, including online mattress stores and makers, high-end sleep shops, and local mattress stores. The mattress advice website the Mattress Underground suggests buying from local mattress manufacturers, another valid option.

I recommend shopping around with three types of sellers to educate yourself -- perhaps one chain or department store, one online store, and one other. Consumer Reports then suggests that you lie on each mattress for at least 15 minutes, because its testers found that the same mattress they liked after 15 minutes was the one that they liked after a month.

Once you've shopped around, buy from a store with a generous return policy. That way, if after following all of the steps here, you're still not happy, you have an out. Many mattress chains, department stores and warehouse stores allow mattress returns now. And most online mattress sellers do because they realize that you have no way of testing their mattresses before you buy them. Make a note of any store's required time frame and also ask about restocking fees and who is responsible for the effort and cost of getting the mattress back to the store.

Why: You're probably going to spend a third of the next decade on this mattress. Even though this all may seem time-consuming, it's worth the effort.

What: There are four main types of mattress, and which you choose is purely preference: innerspring, memory foam, latex or adjustable air. That said, some types tend to work well for people with certain body types or sleep styles. Here are the Good Housekeeping Institute's recommendations for who might like what.

• Innerspring: This is the classic mattress, with metal coils inside and ticking near the surface. Innersprings can be very affordable. The metal coils are usually available from 12 to 18 gauge. The higher the number, the thinner and bouncier the spring. Heavier people have been known to prefer a lower number/thicker gauge. To cut down on movement by a bed partner, choose an innerspring with pocketed, individual coils. They are covered in fabric to reduce movement from one side of the bed to the other. Many innerspring mattresses have "pillow tops," but experts caution that if this layer is thicker than an inch, it will soon sag and develop annoying body indentations.

Best for: those who like an affordable, bouncy-feeling mattress.

• Memory foam: These mattresses are made of viscoelastic polyurethane foam built over a polyfoam core. Memory foam mattresses are known for reducing pressure on your body. They provide a very still feel. Sleepers tend to sink into the foam a bit and be cradled in one position. That cradling and the type of foam can cause some people to heat up as they sleep. The Good Housekeeping Institute says the memory foam layer usually varies from two to six inches thick and that the deeper it is, the more you'll sink. Ask about the thickness and also the density. Density is measured in pounds per cubic foot, with three pounds being lower quality and five pounds higher, according to the Good Housekeeping Institute. If you are concerned about the fact that this type of mattress is made from a chemical process, then look for one that has passed Certipur or Oeko-Tex testing, which means it does not give off excessive chemicals.

Best for: side sleepers and other people who want to reduce pressure, particularly on the shoulders and hips.

• Latex: Latex is a naturally derived material from rubber trees. Latex mattresses are unique in that they can feel very soft and yet also springy and uplifting. There are two manufacturing methods: Dunlop, which is denser and firmer, and Talalay, which is softer and springier. Sometimes the two are layered together. Some manufacturers blend or layer latex on top of man-made foam but still label the mattress as "latex." All-natural latex mattresses are more expensive than some other types. Latex mattresses are common in Europe and growing in popularity in the United States, especially online and in high-end sleep shops.

Best for: people seeking natural materials and strong support.

• Adjustable air: Air beds use air as their support core and then more traditional materials such as foam or ticking as the comfort layer, closer to your body. The air pressure is adjustable, so you can choose a firmer or softer feel at any time and maintain a different mattress firmness from your sleeping partner. Contrary to what you may think based on advertising, several companies make and sell adjustable air beds. Certain air beds have performed very well in Consumer Reports mattress testing, but be aware that consumers have had problems with mold, noise and mechanical failure with some makes and models.

Best for: couples with very different tastes in mattresses.

How: When you shop for a mattress, you should haggle. Yes, it's similar to shopping for a car in more ways than one. Negotiating at chain mattress stores is routine, and you should be able to get 20 percent to 50 percent off. But even at high-end stores and online stores, you can often cut a deal by requesting a recent sale price or asking them to throw in extras. At the very least, go for free delivery and pickup of your old mattress. And, finally, write a "no substitutions" clause into your contract so that after doing all this work you can rest easy knowing you got the mattress you actually wanted.

Leamy is a 13-time Emmy winner and 25-year consumer advocate for programs such as "Good Morning America" and "The Dr. Oz Show."