Choosing a Mattress
Mattresses on sale today have little in common with those of a generation ago. There's a huge variety of materials available in varying degrees of firmness - you can even buy organic mattresses. If you're still sleeping on a twenty year old mattress then decide today to change it.
Everyone has different needs, I certainly can't make the decision for you. However I can give you some information and ideas to consider when you shop. As always, review your options carefully.
Buyer's Guide
Mattress Firmness
Popular modern wisdom says that you should buy as firm a mattress as possible. In fact it isn't that simple. Yes, it's true that a very soft mattress might feel comfortable but does little to give your back the support it needs. However an extremely hard mattress can be just as bad for some people. The amount of back support required will be different for each individual.
You probably already have some idea of the level of firmness that is best for you. To be extra sure, you could invest in a high-tech bed with variable firmness mattress such as the Select Comfort Sleep Number bed.
Remember also that you and your partner might have different needs. You might want to consider buying a matress where each side has a different degree of firmness. That way you get the best of both worlds.
As always, if you have any medical condition then consult your doctor for advice.
Coiled Spring Mattresses
Most mattresses on the market today use coiled springs to support your body. These springs can either be 'continuous' or 'independent'.
In a continuously sprung mattress, all the individual coils are in effect part of one system. This makes the mattress less prone to sagging in one place, however it has the drawback that it usually cannot be as responsive to the shape of your body.
With an independent coil mattress, each coil is a separate entity which gives far more flexible support across the body. Independent coil mattresses tend to be more expensive - be careful of a cheap one, as the coils can sometimes give way quickly.
You also need to consider the number of coils in the mattress. There's no simple "best" number of coils. A larger mattress will obviously need more coils as will a firmer one. Too many coils could result in a mattress that is too firm for you. However it's fair to say that cheaper mattresses often have less coils than their higher quality counterparts, so make sure that you look at these numbers when comparing products.
Memory Foam Mattresses
Memory foam is a relatively recent innovation. Mattresses made with this dense, heat sensitive material mould themselves to your personal body shape to give an even distribution of weight. This gives a good compromise between comfort and support.
Memory foam mattresses are not cheap, but if you can afford it then they can be the best option for some people. More information: memory foam mattresses
If you can't justify the cost of a memory foam mattress, perhaps you could consider adding a mattress topper to an ordinary matteress - this is the approach I've taken and it works for me.
Invest in Quality
This is the best advice I can give on how to buy a mattress. I can't say this too often: you spend a third of your life in bed. Choosing mattresses isn't something to be done on a "buy the cheapest" basis. Don't skimp on something so important, buy the best you can sensibly afford.
Have a great night!