La position de sommeil affecte-t-elle votre santé?août 13, 2019
Surprising truths about tossing and turning
Like most people, Andrew Wellman changes his sleep position many times during the night. And like most people, he seldom realizes it. “The only time I know if I roll on my back is my wife elbows me because I start snoring,” says Wellman, director of the Sleep Disordered Breathing Lab in the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital in Boston.
“A lot of my patients tell me they sleep on their side,” Wellman says. But when position sensors monitor them in the sleep lab, many self-professed side sleepers are on their backs up to 30% of the night, “and they didn’t know it.”
Sleep occurs in a repeated series of cycles, from light to deep to the phase called rapid eye movement (REM), when most dreams occur. We wake after each cycle, even if we don’t realize it.
“Everyone awakens throughout the night five to seven times, after each sleep cycle finishes, and then quickly returns to sleep, often with a brief movement, sometimes turning positions,” explains Shelby Harris, a psychologist and associate professor at the Albert Einstein College of Medicine in New York City and the author of The Women’s Guide to Overcoming Insomnia.
That is, of course, if all goes well.
Pick your preference
Sleep experts agree there is no sleep posture that’s ideal for everyone. Sleep advice sites make a lot of unsupported claims: that sleeping on your right side protects your heart but causes facial wrinkles, that sleeping on your back helps clear the brain of waste products. But there is very little research to suggest that any position is better than another.
For healthy individuals, “it’s just a matter of preference,” says Alcibiades Rodriguez, medical director of the Sleep Center at NYU Langone Health and assistant professor of neurology at NYU School of Medicine. But for a person with pain or certain medical conditions, the right position can become important, Rodriguez says, especially as we age.
People with back pain may get relief by sleeping on their backs, according to the Cleveland Clinic, with a small pillow or rolled-up towel under the knees to alleviate pressure. If that’s not comfortable, then side sleeping — and switching sides during the night — might work. Placing a pillow between the knees can relieve back and hip pain for some people. Most experts advise against stomach sleeping, since it forces the neck to turn to the side and pushes it out of alignment, which can cause back pain. If you must sleep on your stomach, try skipping the pillow, or place another pillow under your pelvis to reduce back and neck strain, the Mayo Clinic advises.
Side sleeping is best for those with specific health problems
Sleep apnea is a potentially serious condition, often triggered by excess weight and lifestyle factors, in which people stop breathing several times a night, typically because their throat muscles relax and block the airway. The brain will wake someone suffering sleep apnea episodes, but they may not remember any of the long breathing lapses, heavy snoring, gasps, and snorts. It can cause daytime fatigue and lead to high blood pressure and heart problems, among other ills. Acid reflux — the backward flow of stomach acid into the esophagus — can also be exacerbated by being horizontal.
“Sleep apnea is worse in the supine position,” Rodriguez says. “And for a person with acid reflux, the supine position is probably not a good idea.”
Pregnant women may want to sleep on their left side. Sleeping on the right can compress the liver, Rodriguez says, and sleeping supine can cause the baby to push on the mother’s diaphragm, making it difficult for her to breathe. Infants should be placed on their backs for sleeping, he says, to help avoid sudden infant death syndrome.
Snoring, which is also worse in the supine position, is by itself not thought to disrupt the sleep of the snorer, Wellman says. “We don’t think it’s a health problem,” he says. “It’s a social problem.” He and other sleep experts offer an old-school trick to help reduce snoring: Sew a tennis ball into the back of your pajamas. If you roll onto your back, the discomfort subconsciously causes you to roll back onto your side, Wellman says.
Another trick to ease snoring, sleep apnea, and acid reflux: Raise the legs at the head of your bed (the cheap approach), or invest in an adjustable bed and raise the back (the very costly approach). Wedge pillows can also help.
Where you sleep matters
“Young kids will sleep anywhere,” says Rafael Pelayo, a sleep specialist at the Stanford Sleep Medicine Center. “Teenagers will sleep anywhere. So will most college students.” The growing bodies and minds of young people require and encourage deeper sleeping, Pelayo explains. That’s why their arousal threshold — what it takes to wake them — is much higher.
“Most people say they sleep best in their own homes,” Pelayo says. Not so with insomniacs. “With all the frustration, the tossing and turning of insomnia, you create negative associations toward your bedroom. You dread going to bed. Then, when you take a trip, you go to a hotel, you’re suddenly away from that environment, and you sleep better.”
I’m not an insomniac, but I, too, have found that I sometimes sleep better in hotels, on mattresses I don’t expect will work for me.
A safe, stress-free environment can play a big role, he says. In a sleep lab, there are cameras all around, and people have wires attached to their heads. “And despite the weirdness of the situation, people often say they never slept so well,” Pelayo says. People may simply feel safer and protected in a hotel or a sleep clinic, he says.
‘That’s my side’
There’s another important factor that matters greatly to people: which side of the bed people sleep.
“The first night you share a bed with somebody, each one of you picks a side of the bed,” Pelayo points out. “Henceforth, you never discuss that anymore. That becomes your side. This becomes my side.” In Stanford’s sleep lab, he says, people who have had a bed partner for years tend to pick one side of the bed and ignore the other half, even though the bed is large and they’re by themselves. And this territorial nature extends beyond the home.
“If you’re traveling, when you get to the hotel room with your significant other, you go, ‘That’s my side, this is your side,’” Pelayo says. Some people even consider it an invasion of privacy if they’re out of town and a bed partner crosses over to their side. “You’ll say, ‘You used my pillow last night while I was away. Why’d you do that?’”
The point is to find the location, environment, and position that works for you. “If you’re comfortable, you’ll know it,” says Harris, the author and Albert Einstein College of Medicine researcher. “Comfort is king. But if you find you’re very restless at night and need to move a lot to get comfortable — say four-plus times a night — then consider asking your doctor for help.”