Have you ever struggled to get comfortable on a pillow that’s too hard, too soft, too full, too flat, too lumpy or just well past its prime? A pillow can make the difference between getting a restful night’s sleep, spending a night tossing and turning, or even waking up with neck and back pain.

Back, side and stomach sleepers may have very different needs and preferences. Finding the right pillow for you involves considering a combination of factors: composition, firmness, contour and coolness.

Sleep experts recommend replacing sleep pillows every year or two since flattened pillows can strain your neck, shoulders and back. Pillows also harbor bacteria and dust mites from the accumulation of hair and body oils over time.

Sleep comfort can be psychological as well as physical. You’ll sleep better knowing the foam in your pillow is CertiPUR-US® certified. That means the foam was screened for relevant chemicals, including flame retardants, that are classified as carcinogens, mutagens or reproductive toxins and are harmful to human health. It’s also made without ozone depleters, PBDEs, mercury, lead and other heavy metals, formaldehyde, or phthalates regulated by the U.S. Consumer Product Safety Commission

It also means the foam has low VOC (volatile organic compound) emissions for indoor air quality (less than 0.5 parts per million).

Some pillows are made of slabstock polyurethane foam, which is manufactured in huge (football-field sized) buns and then cut for shipping and later cut or fabricated as needed. Others are made with molded foam, which is poured into pre-made molds that are shaped to fit the end use — like pouring ice into an ice cube tray. Regardless of the type of foam used, check to be sure the company that makes the pillow you want to purchase uses CertiPUR-US® certified foam.

Once you purchase a new pillow, use a permanent marker to put the purchase date on one of the labels so that you know when it’s time to replace it again.