The wrong pillow can wreck your sleep. Science can help you find the right one.
Your pillow is one of the most powerful tools to help you fall asleep, stay asleep—and even ease your pain and improve posture during waking hours.
If you’ve ever blamed a lousy night’s rest on stress, room temperature, or your mattress, you might be overlooking the smallest—and arguably most influential—piece of your sleep setup: your pillow.
It may look like a basic rectangle of fluff, but sleep scientists say your pillow is one of the most powerful levers you have for regulating how quickly you fall asleep, how deeply you stay asleep, and how your neck, spine, breathing, and brain function long after you wake.
“Sleep is a vulnerable state, and the brain and body need to register a sense of safety and security before allowing the transition—and physical comfort from your pillow and bedding is a powerful cue for that safety signal,” says Wendy Troxel, a senior behavioral sleep scientist at the RAND Corporation.
(There’s a better way to wake up. Here’s what experts advise.)
The right pillow can also ease common complaints like neck pain, back pain, and headaches by supporting the spine’s natural curvature and by creating what clinical psychologist and sleep specialist Michael Breus calls “a no-pressure sleep system.”
Compelling, peer-reviewed research (beyond what pillow manufacturers want you to think) shows additional effects on sleep efficiency, oxygen flow, posture, and even next-day cognitive performance.
Here’s what the science is telling us about why your pillow plays such an outsized role—and how choosing the right one can meaningfully improve both your nights and your days.
National Geographic History Magazine
How your pillow affects how quickly you fall asleep and your sleep quality
Research consistently shows that pillow height and firmness are two of the strongest predictors of sleep quality and the development—or avoidance—of sleep problems.
If a pillow is too high or too firm, Troxel explains, the neck is forced into excessive forward bending. If it is too low or too soft, the neck drops backward or sideways. Either position, she says, can strain muscles, compress joints, disrupt airway openness, and “can lead to micro-arousals throughout the night that fragment sleep and worsen pain and next-day functioning.”
The right pillow, by contrast, helps the body settle into alignment. “A well-fitting pillow helps you achieve a neutral neck position and allows for tissue relaxation and recovery overnight,” explains Matthew O’Rourke, a physical therapist at Simmons University who teaches about sleep-related movement disorders.
(When you go to bed may matter more than how long you sleep.)
Pillow material plays an equally important role because it influences subjective comfort and determines whether alignment is maintained once you fall asleep.
A properly fitted and filled pillow can also reduce muscle aches, improve temperature regulation, and minimize pain signals—conditions, Breus notes, that help the brain transition into sleep more quickly.
It can also help you stay asleep longer and spend more time in slow‑wave and REM sleep—the stages associated with physical repair, learning, and emotional processing.
“A supportive pillow can also reduce nighttime awakenings that interfere with these deeper, more restorative sleep stages,” says Raj Dasgupta, a pulmonary and sleep medicine physician at Huntington Memorial Hospital in California.
Research supports this connection, showing that pillow comfort directly influences the quality of rest people have. It’s so important that, among the 50 percent of participants who reported poor sleep quality in one study, all of them cited pillow comfort as a significant contributing factor.
How your pillow affects sleep disorders
Pillows also influence breathing in ways many sleepers rarely consider. For instance, your pillow’s height, contour, and firmness all affect how open your airway stays during sleep.
This is why Troxel notes that for people who snore or who have mild to moderate sleep apnea, using a pillow that keeps the head and neck gently elevated and aligned—rather than sharply bent forward or backward— “has been shown to reduce sleep-disordered breathing and improve sleep quality.”
(The toll that sleep apnea takes on the body.)
O’Rourke agrees, noting that “the evidence regarding excessive neck extension while sleeping is fairly conclusive for its impact on narrowing the airway and impacting breathing.” Sleeping on an unsupportive pillow, he adds, “also increases the likelihood that the tongue will fall backward and partially block the airway, which can worsen snoring in some individuals.”
These mechanisms help explain why studies examining the use of specific materials, head positioning, or pillows that encourage side-sleeping often reveal reductions in sleep apnea and airway collapse events.
Still, pillows alone cannot treat more advanced sleep apnea or other serious sleep disorders. “It is important to speak to your healthcare provider if you have symptoms of sleep apnea to ensure you have the appropriate treatment plan,” says Rebecca Robbins, a sleep scientist at Brigham and Women’s Hospital in Massachusetts.
How your pillow affects you for the rest of the day
Your pillow also shapes how well your body functions during the day, in part, because when your neck and spine are properly aligned, “it helps relax muscles, maintain an open airway, and reduces pain so you wake up feeling rested,” says Geet Paul, director of interventional pain medicine at the George Washington University School of Medicine.
This especially matters because poor alignment compounds over time—potentially increasing inflammation, impairing mobility, contributing to tension headaches, tightening the shoulders, and worsening chronic neck pain. It also affects your posture.
And because deep sleep is essential for memory consolidation, immune function, metabolic regulation, and emotional processing, Dasgupta notes that anything that disrupts it can impair next-day cognitive performance, including executive function, concentration, mood, productivity, reaction time, and overall energy.
How to choose (and care for) the right pillow for you
While no single pillow height or material works for everyone, there are several evidence‑based principles that can help guide the decision.
The first is recognizing how you sleep. “When picking a pillow, the most important consideration is your sleeper position,” advises Robbins. “Whether you are a back, stomach, or side sleeper dictates the type of pillow we recommend.
From there, determining the appropriate loft (pillow height or thickness) is key. “Ideally, the pillow size should be proportionate to the individual’s body size, shoulder width, and anatomy,” advises Troxel. Side sleepers generally require the most loft; back sleepers do best with a medium loft; and stomach sleepers often need a very low loft or none at all. “If you sleep on your stomach, look for a thin or soft pillow,” advises Dasgupta.
(Why some people are better off sleeping on their sides.)
“Adjustable pillows can also allow people to fine-tune height,” adds O’Rourke. And because it’s difficult to gauge your own alignment while lying down, he suggests asking a partner to take a photo so you can assess whether your neck appears straight, bent forward, or tilted backward.
Paul notes that you also need to take your mattress into account when determining loft because a soft mattress allows the body to sink and often pairs better with a lower pillow, while a firm mattress keeps the body elevated and may require a taller pillow to maintain neutral alignment.
Upgrading your pillow’s fill material can further influence support and comfort. Memory foam, latex, rubber, and spring pillows have all demonstrated supportive benefits in research.
And studies comparing traditional feather pillows and generic polyester pillows against orthopedic or memory-foam pillows show that the latter are more likely to preserve the natural cervical curve, regulate temperature, and improve subjective sleep quality.
“Foam materials also tend to provide more consistent support throughout the night,” adds Stephen Dering, a physical therapist and orthopedic clinical specialist at Massachusetts General Hospital. But latex is another option, he adds, because it “tends to be a more responsive feel to provide support to the neck without the sinking feeling of memory foam” that some sleepers dislike.
These more stable materials may also help reduce strain on spinal nerves, minimize rotator cuff tension, lessen daytime back pain, and decrease morning stiffness.
Pillow maintenance plays a crucial role as well. Dasgupta notes that dirty pillows and pillowcases accumulate dust mites, skin cells, mold, and allergens—factors that can worsen congestion, trigger breathing problems, irritate skin, and subtly disrupt sleep.
To minimize these effects, pillowcases should be washed weekly, and “pillows should be cleaned every few months and replaced every one to two years,” Troxel says—although high-quality latex or foam pillows may last longer.
Paul recommends a quick fold test to determine whether yours is overdue for replacement: “If it doesn’t spring back, it’s probably time to replace it.” And Robbins adds that using a hypoallergenic pillowcase cover is a “trick to keep dust mites at bay.”
Ultimately, she says, the best way to find the right pillow is to try multiple materials and thicknesses to determine which feels most comfortable and supportive to you. “It’s likely that trial and error will be required,” echoes O’Rourke, “but with diligent effort and re-evaluation, individuals can often find well-fitting pillows without paying exorbitant costs.”
