Some characteristics depend on the customer's specific needs, but all mattresses should off proper support. Look for mattresses made of high quality materials that are durable enough to withstand extensive use.
If a firm mattress is required, look for mattresses that have a larger number of higher gauge steel coils. Mattresses that are designed to conform to the natural position of the spine help to evenly distribute body weight during sleep. Very cheap mattresses tend to be of lower quality than mid-range or expensive mattresses, and they typically provide less support and wear out more quickly.
When shopping for a mattress, it's smart to shop in the mid-range of prices. Many people need mattresses that are at least 10 inches thick. Mattresses thinner than 10 inches are unsuitable for most adults, as they cannot support the average adult's body weight properly.
If buying polyurethane or memory foam, choose a mattress with higher density foam, as lower density foams tend to lose durability quickly and add to back pain issues. Innerspring mattresses should have motion isolation, especially when being used by more than one person. Lack of motion isolation causes one person's movements in bed to disturb the other person more easily and often results in poor quality sleep.