A medium-firm mattress, or a firm mattress with a softer pillow top, will give your spine that "just-right" balance of support and cushioning.
An adjustable bed can be a good buy if you need to sleep with your head raised. Doctors sometimes recommend elevating the head to help people with COPD breathe easier, or to prevent nighttime heartburn from GERD. These beds can also allow you to adjust your knees and hips to a 90-degree angle, relieving some of the pressure on sore joints, Levy says.
If you have allergies or asthma, you might have considered buying a bed labeled "hypoallergenic."
"There are a lot of claims made by mattress manufacturers that their mattresses are hypoallergenic or don't support the growth of dust mites, but I don't know of scientific evidence to support these claims," says Paul V.
Williams, MD, a pediatrics professor at the University of Washington School of Medicine and an allergist at Northwest Allergy and Asthma Center in Washington state.
Williams says dust mites will live anywhere there's food -- and that food is your dead skin cells.
Instead of investing in an allergy-free mattress, slip on a washable mattress encasing.
It will form a barrier that prevents dust mites from getting to you. A mattress encasing cuts allergen growth by robbing dust mites of their food supply, Williams says.
And what about those space-age memory foam mattresses, which can cost thousands of dollars?
There is some evidence they can help with back problems and improve sleep, but their advantage over a regular coil mattress is only slight. Where memory foam mattresses can really help you sleep is if you have an active bed partner who is keeping you awake, Decker says.
Foam mattresses reduce motion transfer, letting you lie still while your partner tosses and turns.