A good night's sleep owes much to the mattress. This flat pad or mat is usually placed on the floor or on top of a bed (or metal spring foundation). Historically, a variety of natural materials were used as filling (straw or feathers) for the mattress. But today, mattresses usually have an innerspring core or synthetic materials like latex, viscoelastic or polyurethane. They can also be filled with air or water.
It is recommended that you replace your mattress after every 10 to 13 years. Spring bases require replacement every 12 to 13 years, while slat bases require replacement every once every ten years. For hygienic purposes, however, it is wise to replace any mattress once every 10 years, regardless of what base type it is. Peaks, dips, or lumps in your mattress from day-to-day use might also warrant mattress replacement if you frequently wake up feeling stiff or have regular backaches. As you grow older your body changes and with that your needs. An older body will better appreciate a softer, but still firm, mattress to protect the pressure points. Mattresses that are too soft will also create difficulties for older persons when getting out of bed.
When shopping for a mattress, it is important to go for superior quality. Be clear whether you want a soft, medium or hard mattress. Get the bed size correct and make sure any mattress you buy has at least a 10-year warranty. A soft mattress will allow your body to sink in and it has less dense inner foam core with more fill around the foam core. A medium mattress will allow your body to sink in but also offer a good amount of support. It will have more dense foam core and less fill around the foam. On the other hand, a firm mattress will allow for complete body support with very little fill between the foam core and the mattress cover.
A common innerspring mattress consists of three components: the spring core, the foundation and the upholstery layers. The core of the mattress supports the sleeper's body. Modern spring mattress cores, often called "innersprings" are made up of steel coils. The foundation can be of box springs, wood or a combination of wood and steel. Box springs have a rigid frame with extra-heavy springs (soft and could sag). Sometimes manufacturers put high-density block foam under the coils for a firmer foundation. Wood foundations are firm and called zero deflection units in the industry since these consist of seven or eight support slats that offer firmness and stability. The upholstery layer is also known as the comfort layer as it provides cushioning and comfort.
Air beds or air mattresses use air chambers instead of springs for support. Price ranges vary from very affordable to high-end. Some air beds can even adjust the firmness of the mattress. Mattresses made of latex (natural rubber) are very expensive and also need an expensive flexible-slat base. But a pure latex mattress can be expected to last 20 to 25 years. A latex mattress may be a good option for allergy sufferers because they're less likely to harbor mould and dust mites. The mattress doesn't wobble (reducing partner disturbance) as well. A latex overlay with a firm spring mattress is a good, economical option.
But the buzzword in mattresses today is memory foam mattress or viscoelastic. Viscoelastic foam was developed by NASA almost 30 years ago, but it is just beginning to work its way into the mattress market today. Made from polyurethane it is less 'springy' and slower to recover, hence called 'memory foam,' as it 'remembers' your shape for a while after you've moved. So a viscoelastic mattress (that has a layer of viscoelastic attached to another material, usually polyurethane foam) or viscoelastic overlays (to put on your present mattress) often make for a very comfortable bed with minimum partner disturbance. Some, however, feel it's like 'sleeping on wet or hard sand'. But viscoelastic mattresses are often used in some hospitals and nursing homes to help prevent pressure ulcers caused by lying in the same position for a long time.