You spend a substantial part of every 24-hour period in bed, trying to get a good night's sleep. If you are tossing and turning, or if you're getting up in the morning with aches and pains, consider the condition of your mattress. Muscle aches are often caused by a mattress that's too hard for you, while joint stiffness may be caused by a mattress that's too soft and doesn't provide enough support. Everyone is different, though, and a mattress that is too firm for one sleeper will seem too soft for another. Use your instincts on this—you very likely know quite well if you need a firmer or softer mattress. Don't lose another night's sleep on a mattress that doesn't suit your needs.
First Step: Clean Your Mattress
Before you do anything else with your mattress, clean it thoroughly.
Start by removing the bedding, them moving the mattress and box spring (if you're using one) off the bed frame. Use a vacuum with an upholstery attachment to clean both the mattress and box spring thoroughly (and the key word here is thoroughly). No one likes to think about it, but most mattresses are filled with dust particles (consisting in large part from human skin cells), as well as dust mites. You will be surprised later on to find how much better you sleep once your mattress is thoroughly cleaned. Most people have some type of allergies to the substances that find their way into mattresses, and cleaning really can have an impact on sleep quality.
Take this opportunity to also vacuum the bed frame itself, including footboard and headboard. Wipe the hard surfaces with a damp cloth.
Making a Mattress Firmer or Softer
If your mattress is much, much too firm or soft for your liking, the following techniques might not be enough to fully satisfy you. But you'll be surprised to how much you can improve your mattress.
Making Your Mattress Softer
Purchase a pillow-top cover that slips over the top of a mattress to make it feel much softer. A pillow top is fashioned from specially contoured foam covered with protective, quilted fabric. You can choose from several styles and thicknesses. The thickest foam provides the softest results. Memory foam mattress toppers, constructed of polyurethane, mold to the shape of your body. They also can help relieve pressure points, making sleep more comfortable.
Natural fibers wick warmth away from your body, making you feel cooler. A pillow top filled with cotton is a good choice if you are too warm at night. A latex eggshell mattress topper adds softness while allowing air to circulate under you.
Warm up the room. Some mattresses, especially memory foam, are temperature sensitive, and will "give" more if the room temperature is warmer. Another option is to add a heated mattress pad.
Break in the mattress. New mattresses are naturally firm, and they will soften up a bit under heavy use. Some people have reported success by allowing their children a few trampoline sessions.
Rotate or flip the mattress. One area of the mattress may compress a bit under long use, and simply rotating it head to foot or flipping it over may provide a more cushiony section to sleep on.
Making Your Mattress Firmer
Eliminate the box spring. Most modern mattresses have an inner design with built-in coils that don't really require a box spring. You can get rid of the box spring altogether and install a sheet of plywood or rows of closely spaced wooden slats on the bed frame, then rest the mattress directly on the platform. Wooden slats are better than plywood for this, as they will allow the mattress to "breathe."
Replace the box spring. Sometimes the problem isn't really with the mattress at all, but with a box spring that has lost its tension and is allowing the mattress to "give" more than you want. This will be most evident if you find your mattress sagging in the middle. And because box springs are relatively inexpensive, replacing one is a fairly cost-effective fix.
Put a bed board between mattress and box spring. Putting a solid sheet of thin wood between the mattress and box spring improves the rigidity of a mattress. This can, however, reduce that mattress' ability to "breathe," so be prepared to clean it often and flip the mattress frequently to make sure it doesn't develop moisture and mold problems.