The Best Side to Sleep on According to Science

The best side to sleep on is the one that helps you get the most sleep. But side sleeping is beneficial for many health issues, if you can make it work for you.
Published
2023-03-09
21 MINS
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Chester Wu, MD, Rise Science Medical Reviewer
Our Editorial Standards
We bring sleep research out of the lab and into your life. Every post begins with peer-reviewed studies — not third-party sources — to make sure we only share advice that can be defended to a room full of sleep scientists.
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Updated Regularly
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Woman sleeping on left side and man sleeping on right side which are two sides to sleep that offer benefits

Sleep is important for your health, but which side exactly should you be sleeping on for concerns like your heart health, digestion, acid reflux, sleep apnea, and more? 

For some health issues, there’s no one sleeping position that’s better than another. But for others, science has found a potential winner, and your sleeping position may be able to make a difference to your symptoms and how well you sleep at night. 

Below, we’ve rounded up everything we know about the best side to sleep on. Plus, we explain why, in most cases, you’re far better off focusing on sleep hygiene over position to get the best night’s sleep possible. Sleep hygiene will help you fall and stay asleep more easily, whichever position you use. We’ll dive into how the RISE app can help you nail this. 

What’s the Best Side to Sleep on?

Here’s the best sleeping position for common health worries. 

For Digestion

Side: Left side. 

Why? More research needs to be done, but it seems the left side is best for digestion. When you’re on your left, gravity can help move food along from your small intestine to your large intestine. 

Sleeping on your side or back may be best if you’re bloated or have stomach pain, as this avoids putting pressure on the painful stomach area.

Even better than your left side is sitting or standing up, though. This reduces the risk of heartburn and means food can travel better through your digestive system compared to being horizontal. Try sitting or standing, instead of laying down, after meals. 

A lack of sleep can tank your digestion, however. It’s been linked to upper and lower GI symptoms, diarrhea, and constipation. Sleep deprivation has also been linked to more serious digestive conditions like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). 

So, while the left side may be the best side, if you can’t get the sleep you need on your left, don’t sacrifice shut-eye for it. 

We’ve covered more on the best side to sleep for digestion here and how to improve gut health naturally here.

For Acid Reflux and GERD  

Side: Left side.

Why? Acid reflux happens when stomach acid washes up into your esophagus. When this happens chronically, you may have gastroesophageal reflux disease (GERD). Acid reflux and GERD can cause heartburn, stomach pain, and general discomfort, making it hard to sleep in any position. 

But, sleeping on your left side may help. When you lay on your left, your stomach is lower than your esophagus, making it harder for stomach acid to rise up into it. 

Research from 2022 found left-side sleeping helped those with reflux have more reflux-free nights. Sleeping on your right may make symptoms worse. 

If you can’t sleep on your left side, try sleeping on your back with your head elevated, which can reduce heartburn and the sleep disturbance it causes. 

We’ve covered more on how to sleep with acid reflux here. 

For Lower Back Pain

Side: Left or right side.  

Why? Sleeping on your side, either side, can help reduce lower back pain. 

One small study asked those with lower back pain to sleep on their sides with a pillow between their legs, and those with upper back pain to sleep on their backs with a pillow under their knees. After sleeping in these positions for four weeks, 90% of participants reported significantly less back pain.

If you’re a front sleeper, switching to your side may help to reduce back and neck pain, as side sleeping puts less pressure on these areas. 

If you’re a back sleeper, try elevating your knees with a pillow to help align your spine and using a pillow to support your neck

Learn how to sleep with lower back pain here.

For Snoring 

Side: Left or right side. 

Why? When you’re on your back, gravity can pull soft tissue into your airways, obstructing them and making it more likely you’ll snore. 

Research shows sleeping on your side can reduce both how much you snore and how intense this snoring is. 

If you can’t fall asleep on your side, try sleeping on your back with your head elevated, which can also reduce snoring. A 2021 study found sleeping with an adjustable base bed with their head elevated helped snorers reduce their snoring duration, wake up less often during the night, and get more deep sleep.

We’ve covered reasons why you’re snoring all of a sudden here and how to stop snoring here.

For Sleep Apnea

Side: Right side. Sometimes either side. And sometimes on your back. 

Why? When you have obstructive sleep apnea, your airways close off during the night, temporarily stopping you from breathing. Your brain eventually notices the low oxygen levels and wakes you up to kick-start your breathing again.  

When you’re on your back, it’s easier for your tongue to fall back and block your airways and for soft tissue to hang down and obstruct your breathing. 

So, sleeping on your side can reduce how many of these sleep apnea episodes you get each night, and avoiding the back sleeping position may even help eradicate the condition in some patients. 

Research shows sleep apnea episodes can happen twice as often when sleeping on your back compared to on your side. 

This doesn’t happen for everyone, however. Some have what’s called position-dependent sleep apnea. This is defined as a difference of 50% or more in apnea index (the measure of sleep apnea severity) between back sleeping and non-back sleeping. It’s thought about 56% of patients have position-dependent sleep apnea. 

The higher your BMI and the more severe your sleep apnea, the less likely you are to have position-dependent sleep apnea. (You can learn about sleep apnea and weight gain here).

More research needs to be done, but sleeping on your right side in particular may help to reduce symptoms of sleep apnea more than sleeping on your left. One study found right-side sleeping decreased the amount of sleep apnea events in those with moderate to severe levels of the disease. 

While back sleeping is usually advised against if you have sleep apnea, if you’re sleeping with a full-face continuous positive airway pressure (CPAP) machine, it may be the only position you can sleep in. Special pillows can make side sleeping with a full-face CPAP machine easier, or you may be able to use a nasal CPAP machine instead, which is easier to lay on your side with. 

Speak to your healthcare provider about how to get rid of sleep apnea and the best treatment for you. 

To dive deeper, check out what sleep position is best for sleep apnea here.

For Heart Health 

Side: Left or right side, although more research needs to be done.  

Why? The jury’s still out on the best side to sleep on for heart health.

Those with heart failure may naturally prefer sleeping on their right side, as they can experience pain and discomfort when on their left side. 

On the other hand — or side — sleeping on your left may help blood flow better back into the heart, as you’re not putting pressure on the right side where this happens. 

Most of the time, getting enough sleep is going to be much more important than sleeping position when it comes to heart health.

For Brain Health 

Side: Left or right side. 

Why? More research needs to be done, but sleeping on your side may help your brain clear out waste more effectively, helping to lower your risk of conditions like Alzheimer’s disease. 

Research in rats found glymphatic transport (or the removal of brain waste) was most efficient when sleeping on the side, compared to sleeping on the back or on the front.

Getting enough sleep is vital for brain health, though. So, don’t sacrifice shut-eye if you can’t fall asleep on your side. 

While sleeping on your side may be the best position for your brain, sleeping on your back may be better than the front, according to the research in mice.

When Pregnant 

Side: Left side. Or potentially either side. 

Why? Sleeping in any position can be hard when you’re pregnant. Sleeping on your left is sometimes recommended for pregnant women, though. 

Research from 2020 found sleeping on your left was associated with a lower heart rate and higher heart rate variability — the variation in time between each heartbeat. Higher variability is usually a sign of heart health. 

But more research needs to be done to know for sure whether the left is better than the right side. A 2019 meta-analysis found going to sleep on the left or right appears equally safe. 

Back sleeping is usually advised against as it compresses the inferior vena cava vein, which can cause high blood pressure for you and reduced blood flow to the baby. The meta-analysis above found back sleeping was linked to late stillbirth. 

Sleeping on your front in the later stages of pregnancy is usually advised against, too — and most likely impossible anyway.  

If you find side sleeping uncomfortable, try sleeping with a pregnancy or full-body pillow to take pressure off your joints and back.

If you’re expecting, learn more about how to sleep when pregnant and how to get energy when pregnant

When healing from a c-section, sleeping on your side, back, or on your back with your head elevated may be best.

For Skin 

Side: On your back.  

Why? When you sleep on your front or on your side, your skin is smooshed into your pillow, which can cause fine lines and wrinkles. You might have noticed “sleep lines” when you wake up, showing how squashed your skin has been during the night. 

Sleeping on your back means nothing is tugging on your skin in your sleep. 

If you’re a side sleeper, invest in a silk pillowcase. This can reduce the friction and tugging a normal pillowcase causes. Want to forgo a pillow altogether? We cover the pros and cons of sleeping without a pillow here.

Beyond wrinkles, sleeping on your back may also help keep your skin clear as your pillowcase can absorb oil and dirt and transfer this to your skin.  

The best way to look after your skin is to get enough sleep overall, though. We’ve covered how to prevent wrinkles here and how to get clear skin overnight here.

Leg Cramps

Side: Any position where your toes aren’t pointed away from you. 

Why? When your toes are pointing away from you, your calf muscles are shortened and this may trigger leg cramps at night. 

Whichever position you choose, try to sleep with your feet flat. This could mean on your side, on your front with your feet hanging off the bed, or on your back with a pillow propping up your feet. 

We’ve covered more on the causes and treatments for leg cramps at night here. 

On Your Period 

Side: Left or right side.  

Why? Getting enough sleep on your period can sometimes feel impossible with cramps, bloating, hormones, and anxiety all potentially keeping you awake. 

Sleeping on your side may help. Sleeping in the fetal position — on your side with your knees tucked slightly in — can help relax your abdominal muscles and ease cramps. 

Side sleeping may also help reduce leakage as blood is less likely to fall forward or backward. Even just knowing you’re less likely to leak may help ease anxiety about it and help you drift off. 

Need more sleep tips for this time of the month? We’ve covered how to sleep on your period here.

Postnasal Drip

Side: On your side or with your head elevated.

Why? Postnasal drip is when mucus gathers at the back of your throat. It can cause congestion, a cough, or a sore throat, and interfere with your breathing at night.

Sleeping on your side or sleeping with your head elevated will help keep your airways open and stop mucus from building up as much at the back of your throat.

For Allergies

Side: Left or right side.

Sleeping on your side may help keep your airway open while you sleep and can promote nasal breathing, which will help filter out allergens.

Sleeping on your back with your head elevated is the best position to sleep with allergies. When your head is elevated, gravity can help drain congestion away, helping you breathe more easily.

Prop your head up on some extra pillows. Or try sleeping in a recliner or on an adjustable bed with the head propped higher. The idea is to keep your blood flowing down away from your sinuses and to help keep your sinuses more open.

We've covered why allergies are worse at night and how to fight allergy fatigue here.

For Aging 

Side: Any position that helps you get enough sleep.

Why? There’s no one position that’s best as we get older. You may develop health conditions that require you to sleep on your left side (like GERD) or on either side (like sleep apnea). 

But if not, finding a comfortable position is the most important thing. As we age, sleep is harder to come by. And you don’t want joint issues waking you up or a bad back stopping you from falling asleep. 

Focus on finding the position that lets you get the most sleep possible. Experiment with pillow positioning to take pressure off your joints and keep your spine aligned. 

For Weight Loss 

Side: Any position that helps you get enough sleep.

Why? Sleep and weight are closely linked. When you don’t get enough sleep, you eat more calories, burn fewer calories, gain weight, and struggle to lose excess weight you already have.

So, the best sleep position for weight loss is the one that helps you get enough sleep. 

One caveat to this is if you’re overweight, you’re more likely to snore and have sleep apnea. And sleeping on your side may help to reduce the symptoms of both. 

We’ve covered more on sleeping positions to lose weight here.

What’s the Worst Sleeping Position for You?

Ultimately, the worst sleeping position for you is the one that stops you from getting the sleep you need. If laying on your left means you can’t fall asleep because shoulder pain is keeping you up, it’s not the best position for you. 

But, assuming you can sleep in any position, you might want to avoid sleeping on your front. 

Stomach sleeping puts a lot of pressure on your back, neck, and shoulders. If you have indigestion, cramps, or bloating, it may cause pain and discomfort as you put weight on your stomach. And if you have lower back pain or you’re in the later stages of pregnancy, it’s advised you avoid stomach sleeping altogether. 

If you’re a stomach sleeper and really can’t sleep in any other position, here’s how to make it better for you: 

  • Use a thin pillow (or sleep without a pillow) to keep your head in line with your spine. 
  • Put a thin pillow under your hips to keep your spine in a neutral position.
  • Keep your legs straight and neutral, rather than bent and twisted. 
  • Avoid tucking your arms under your pillow and try sleeping with them by your sides to avoid putting pressure on your shoulders. 
  • Switch which way you face throughout the night to avoid neck stiffness. 

Is Sleeping Position Important?

RISE app screenshot showing when to get and avoid bright light
The RISE app can guide you through 20+ sleep hygiene habits.

The position you sleep in can affect your sleep, and therefore your energy levels, mood, and overall health and well-being. And the right position may offer pain relief if you’re suffering from cramps, acid reflux, or lower back pain. So, it is important. 

But, if you’re uncomfortable in a certain position and can’t drift off, you’re not going to get the sleep you need. And that is a bigger problem. 

We argue, while sleep position is important, sleep hygiene and meeting your sleep need are much more important. 

Sleep hygiene is the set of daily behaviors you can do to get a good night’s sleep. If your sleep hygiene is poor, you may struggle to fall asleep in any position and may wake up during the night. 

Your sleep need is the individual amount of sleep you need each night. It’s determined by genetics, just like height and eye color, and it’s different for everyone. One study suggests the average sleep need is 8 hours 40 minutes, plus or minus 10 minutes or so, but 13.5% of the population may need 9 hours or more sleep a night.

If you’re not meeting your sleep need at night, it doesn’t matter which position you’re sleeping in, you’re still going to struggle with a lack of energy, poor focus, and a low mood the next day — not to mention the long-term health impacts of sleep deprivation. 

Your sleep posture, therefore, isn’t going to make or break your sleep or health. And it’s not going to give you the same health benefits as getting a full night’s sleep with good sleep hygiene will. These are the things that make the biggest difference to your energy and health, and these are the things you should focus on first. 

There’s one final thing: anxiety is the enemy of sleep. It can easily keep you up long into the night. So, if you’re worried about the right sleeping position, or stressed about rolling onto your front in the night, this anxiety can keep you up and do more damage than the “wrong” sleep position itself. 

The bottom line? The best side to sleep on is whichever side helps you meet your sleep need. And we say you’re far better off focusing on sleep hygiene to get a better night’s sleep than worrying about sleep positions (unless you have a health condition, of course).  

The RISE app can work out your individual sleep need based on a year’s worth of phone use behavior and proprietary sleep-science-based models. You’ll get a number to aim for each night in hours and minutes.

RISE can also guide you through 20+ sleep hygiene habits and when exactly to do them each day to make them more effective. We’ll cover more on what to do next.

RISE users on iOS 1.202 and above can click here to view their sleep need.

RISE users on iOS 1.202 and above can click here to set up their 20+ in-app habit notifications. 

How to Sleep Comfortably on Your Side?

Sleeping on your side may be the best for your health, but it’s not always easy. 

Here’s how to make side sleeping work for you: 

  • Use a thicker pillow to keep your head in line with your spine.
  • Sleep with a pillow between your legs to keep your spine aligned. 
  • Buy a medium-firm mattress that doesn’t put too much pressure on your joints. If you experience shoulder or hip pain, you may need a softer mattress. 
  • Swap sides throughout the night if you get shoulder pain on the side you’re sleeping on. 
  • Tuck your knees in slightly, rather than having them dead straight, to reduce pressure on your back and support the natural curve of your spine. 

We’ve covered more on proper pillow positioning for sleeping here.

How to Train Yourself to Sleep on Your Side?

Whether you’re a diehard back sleeper who’s been told to sleep on your side, or you manage to drift off on your side only to wake up on your stomach, positional therapy could help. 

Positional therapy is anything that keeps you sleeping in the right position. It includes: 

  • Special pillows that encourage side sleeping 
  • A vest or belt with a hard shape on the back that makes back sleep uncomfortable or impossible 
  • A device that vibrates when you roll onto your back 
  • Foam wedges that stop you from rolling onto your back 

Positional therapy is often used for people who snore or who have sleep apnea.  

Outside of special pillows and devices, you could ask your partner to gently roll you onto your side if they catch you sleeping on your back during the night. Or use firm pillows to stop you from changing positions in the night. 

You can also experiment with the best pillow and best mattress for you to ease pain on pressure points and make side sleeping more comfortable. 

And, most importantly, don’t stress too much if you wake up in a different position. Getting enough sleep overall is more important than getting it on the “right” side.

How to Get Better Sleep?

RISE app screenshot showing you when to limit caffeine intake
The RISE app can tell you when to stop drinking coffee and alcohol, working out, and eating for better sleep.

Whether you’re sleeping on your left or staying a firm front sleeper, the secret to getting a good night’s sleep is sleep hygiene. 

Here’s what to do: 

  • Get bright light first thing: Get at least 10 minutes of light as soon as possible after waking up, and 15 to 20 minutes if it's overcast or you’re getting light through a window. This will reset your body clock for the day and help you feel sleepy come bedtime.
  • Avoid light close to bedtime: Bright light suppresses the sleep hormone melatonin and can keep you up in the evening. Dim the lights and put on blue-light blocking glasses 90 minutes before bed. 
  • Avoid caffeine, large meals, intense exercise, and alcohol too late in the day: These common sleep disruptions can keep you up or wake you up during the night. 
  • Do a calming bedtime routine: Do relaxing low-stress activities in the run-up to bedtime like reading, yoga, journaling, or listening to music. Try RISE’s audio guides, which walk you through relaxation techniques for better sleep.
  • Keep your bedroom dark, cool, and quiet: Create the perfect sleep environment by setting your thermostat to 65 to 68 degrees Fahrenheit, using blackout curtains, and wearing earplugs and an eye mask

The RISE app can guide you through 20+ sleep habits each day.

RISE users on iOS 1.202 and above can click here to set up their 20+ in-app habit notifications.

Get the Sleep You Need in Any Position

The side you sleep on can be important, especially if you have a health condition. But what’s even more important is meeting your sleep need each night. So, we say, whichever side helps you get the most sleep is the best side to sleep on for you.  

To help you fall asleep in any position, maintain excellent sleep hygiene. The RISE app can tell you when to do 20+ sleep hygiene habits to make falling and staying asleep easier.

This’ll make meeting your sleep need easier each night, and in turn, be one of the best things you can do for things like your digestion, brain health, skin, and weight — not to mention your energy and overall health and wellness.

Summary FAQs

What is the healthiest sleeping position?

Sleeping on your side may be healthiest for your heart, brain, digestion, and if you snore, have sleep apnea, lower back pain, or you’re pregnant. But the healthiest sleeping position is the one that helps you get enough sleep each night.

Which side is best to sleep on? Left or right?

Sleeping on the left side may be best for acid reflux and digestion, and when pregnant. Sleeping on the right side may be best for heart health. And sleeping on either side may be best for brain health, and if you snore, have sleep apnea, or have lower back pain. But the best side to sleep on is the side that helps you get enough sleep each night.

Best side to sleep on for heart

More research is needed to know the best side to sleep on for your heart health. Laying on your left may help blood flow better back into the heart, but those with heart failure may find it uncomfortable. Most of the time, getting enough sleep is going to be much more important than sleeping position when it comes to heart health.

Best side to sleep on when pregnant

The best side to sleep on when pregnant may be the left. It’s linked to a lower heart rate and a higher heart rate variability, both of which are signs of heart health. But some research says either side is equally healthy. Sleeping on your back may increase stillborn risk, and sleeping on your front in the later stages of pregnancy is usually advised against (and impossible).

Best ways to sleep on your side

The best ways to sleep on your side include using a thicker pillow that keeps your head in line with your spine, sleeping with a pillow between your knees to keep your spine aligned, and using a medium-firm mattress to take pressure off your joints.

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