Similar to a new hat, jeans or pair of shoes, your new mattress may need to be broken in to maximize its comfort. Breaking it in is a simple process, requiring just a little more than time, and may differ by mattress type.
You might want to run out and buy new sheets for your new mattress, and that's fine, but don't use them yet. New fitted sheets can be tight, acting like a girdle, for example, and your big, rectangular purchase needs loose or baggy bedding so that it can move, stretch and bend naturally as it conforms to your body. Even the mattress pad -- usually a requirement for warranty coverage -- must be loose-fitting. Rather than starting with a tightly fitted pad, it may be best to use one with elastic straps that simple hook under each corner, allowing the padding, covering, foam or coils underneath to flex.
Just You Wait
Your previous mattress likely was firmer or softer -- and lumpier -- than your new one, and that's what your body became accustomed to. Now, as you lay there awake, and possibly a little uncomfortable, you may be second-guessing the investment. But give it time, about a week -- or maybe two, for a pillowtop option -- depending on the retailer's or manufacturer's suggested break-in period. Within this time frame, the bed should conform to your body, and vice versa.
If you chose your mattress based on how the one in the showroom felt, and the one you're now sleeping on doesn't feel the same, don't panic. Showroom mattresses are well broken in by person after person, such as yourself, who sat, lay and rolled on them, and are good examples of what you can expect when the waiting period is over.
If the mattress waiting game isn't for you, you may prefer one that retains its shape under your weight from day one. In this case, contemplate a memory foam mattress or one with a latex and memory foam blend. Often, these hold their shape, again, under yours, relatively well.
One condition that normally doesn't change by mattress type is how you support it. An appropriate boxspring or foundation is imperative for comfort and warranty, when you're using a standard bed frame.
Don't Wait Too Long
Not only might many manufacturers or retailers suggest a short break-in or trial period for their mattresses, but they typically have an inflexible return or exchange deadline, which may range from 21 days to a month or two, for example, for nondefective products. If your body doesn't adjust to the coils, foam or firmness, don't miss the chance to trade it for a better option -- it's your money and comfort on the line, after all.