What Is the Best Sleeping Position?

You probably already know that falling asleep in a funky position can leave you feeling sore the next morning, but your sleeping position can reflect your overall health and even your ability to breathe easily at night. Luckily, you can optimize your sleep posture by making small adjustments to support your spine and neck, open your airways, and help you wake up feeling well-rested.

So, what is the “best” sleeping position to get you there? It’s a tricky (if not impossible) question to answer, since everyone’s body, health, and preferences are different. But according to Jennifer Martin, PhD, spokesperson for the American Academy of Sleep Medicine and professor at the Herbert Wertheim College of Medicine at Florida International University, what’s best for you hinges mostly on two factors: what position allows you to breathe easily, and what position is the most physically comfortable for your body.

“It’s pretty individualized,” Martin says. “Not everyone is comfortable in the same position.”

What’s more, the “best” sleeping position can change throughout a lifetime and will balance your body’s needs. For example, shoulder pain sometimes becomes a problem during side sleeping as people get older, which can conflict with the common advice that people with sleep apnea should avoid sleeping on their backs, according to Dr. David McCarty, MD, FAASM, chief medical officer of Rebis, a sleep medicine clinic. And while stomach sleeping is often considered the position that causes the most neck and back strain, its many people’s go-to position that gets them to fall sleep fast.

“Often, sleep position becomes about avoiding the position that causes the most problems,” McCarty says.

To help you weigh all the pros and cons of each sleeping position, we spoke to sleep medicine experts and looked at research for guidance on how you can position your body for more comfort, and why you shouldn’t overlook the importance of pillows.

Why does sleeping position matter?

“It’s a seemingly simple question, but it requires kind of a thoughtful response,” McCarty says. “Sleeping position can affect the physiology of a number of different organ systems.”

Arguably the most important thing to consider when sleeping, according to McCarty, is how the position of your body affects your breathing, and also what your default sleeping position may be telling you about your overall ability to breathe easily. The posture of your neck, jaw, and all the bones surrounding your airway should be positioned in a way that supports easy, peaceful breathing.

“It’s not just about the position of your body,” McCarty says about finding the proper sleeping position. “It’s about the position of your jaw and your tongue.”

This is especially true for people with symptoms of obstructive sleep apnea, a disorder that is marked by disrupted breathing during sleep. It’s estimated to affect roughly 30 million American adults and frequently goes undiagnosed.

When it comes to finding the most comfortable sleeping position, it may also matter a little more for people regularly experiencing trouble sleeping.

“For people with insomnia and problems with pain, we work really hard with making sure they can get in a comfortable position,” Martin says.

Sleeping on your back

Back sleeping promotes spinal alignment (as long as you properly support your head and neck with a pillow) and some research has shown it may help reduce lower back pain. People who experience neck or shoulder pain may also want to experiment with back sleeping (also called the supine position), since it takes pressure off joints by distributing your body weight more evenly.

However, back sleeping isn’t right for everyone. In particular, it can cause more interference with airflow compared to other sleeping positions, which causes some people to naturally “self-select” against sleeping on their back, according to McCarty.

For similarly air-related reasons, it’s often not recommended for people with obstructive sleep apnea because it exacerbates its symptoms, which include breathing interruptions and snoring. This is evident from sleep studies on people with sleep apnea, according to Martin.

“A lot of time, we’ll measure that their sleep apnea is worse when they’re on their back versus when they’re in other positions,” she says.

Back sleeping also isn’t recommended in the later stages of pregnancy, according to the American College of Obstetrics and Gynecology, since the growing weight of your uterus can put pressure on an important blood vessel.

Sleeping on your side

Side sleeping (lateral position) is considered the most popular sleeping position, and it’s beneficial for many reasons. For people with acid reflux (gastroesophageal reflux disease or GERD), research has shown that sleeping on your left side, in particular, can relieve symptoms. If you’re pregnant, your doctor may also recommend you sleep on your left side.

If healthier breathing is your goal, the side sleeping position may make it easier. McCarty points to this position as a natural way for many people to limit the effects of gravity and open the airway during sleep. For example, nasal breathing, which has more health benefits compared to frequent breathing through the mouth, is often easier when you’re on your side because it naturally opens airflow.

Sleeping on your stomach

Lying on your stomach may feel comfortable for some people, but experts tend not to recommend it because it strains the spine and puts the neck in an awkward position overnight, which can lead to pain in the neck, shoulders, and back.

If sleeping on your stomach is the only way you’re able to sleep, you can reduce the pressure on your back by putting a pillow under your hips and lower stomach, according to information from the Mayo Clinic.

Also consider which pillow you’re using under your head, and make sure it isn’t too tall or cushioned, which may cause your neck to flex too much. If you’d like to experiment with side sleeping or try to adjust your sleeping position all together, you can also use pillows as “bumpers” to help you stay put, according to information from the Cleveland Clinic.

Best sleeping positions for back and neck pain

A large review of available research found that lying on your side is linked to the least amount of spinal symptoms from sleep, including pain and stiffness when you wake up.

Sleeping on your back is also considered a good position for keeping your neck, shoulders, and hips straight, which minimizes the strain on your spine that causes pain. But whatever your preferred sleeping position, you should look at pillows as an important tool that can help your body’s alignment and also help you transition to a new position. This may be especially true if you are a stomach sleeper and frequently wake up with neck, shoulder, or back pain.

“We can’t underappreciate how important pillows are,” Martin says. They’re something that can be easily adjusted throughout the night and should be propped up in a way that supports your neck and back. For example, Martin says that side sleepers may benefit from putting a pillow under the top of their knee.

“That can help you have a more aligned position in your spine and stay comfortable longer,” she says. If you struggle to fall asleep because you’re uncomfortable, you may also want to try a body pillow, according to Martin.

“It helps with alignment, and some people find they’re more comfortable throughout the night than if they sleep through the night without it,” she says. (Think those big, long pillows that cradle your body.)

For back sleepers with back pain, the Mayo Clinic suggests placing a pillow under your knees to help relax your back muscles and maintain the natural curve of your lower back while keeping your neck supported.

In general, McCarty says you’ll want to sleep with your neck in a neutral position, and not have it flexed. Too much extending and flexing over time will put more wear on your spine and neck, making neck or back pain worse and potentially causing other health problems.

Best sleeping positions for acid reflux

Martin says that people who have acid reflux tend to benefit from having their head propped up a bit. You can achieve this by propping up your head, neck, and shoulders with pillows, or by investing in an adjustable mattress that you can elevate.

Some research suggests that sleeping on your left side, in particular, may reduce heartburn and symptoms of GERD, which happens when stomach acid travels back up through the esophagus.

Best sleeping positions for sleep apnea

It’s thought that back sleeping isn’t ideal for people with sleep apnea. This is because people with obstructive sleep apnea symptoms (gasping, snoring, and other breathing disruptions that cause you to wake up frequently during the night) experience more airway collapse, which is naturally a little compromised in the back-sleeping position.

“For mild sleep apnea, we would recommend they sleep on one of their sides,” Martin says. She added that people experiencing any symptoms of a sleep disorder should be evaluated by a sleep specialist to find the cause and treatment, if needed.

However, people with moderate or severe cases of sleep apnea often need treatment and will wear continuous positive airway pressure (CPAP) masks during the night, which may make-or-break which sleeping position is most comfortable. According to Martin, depending on the type of CPAP mask someone wears or how large it is, some people with sleep apnea will have a harder time sleeping on their side because it puts pressure on the mask, which can cause it to leak air.

“If you’re treating your sleep apnea,” Martin says, “just focus on comfort.”

How to know what sleeping position is right for you

Both Martin and McCarty say that the best sleeping position for you is the one that makes you the most comfortable. That means finding one that balances your breathing, minimizes soreness, and supports your overall well-being.

“I stress the importance of what works for you,” McCarty says. If your current sleeping position feels comfortable to you and works with your individual physiology, he says, “that’s probably more sensitive than any blanket advice.”

Sleeping position FAQs

This story was originally featured on Fortune.com