The Best Sleeping Position for Your Body: Side, Back or Stomach

The best sleeping position for most people is on your side, with your spine kept roughly straight by a pillow of the right height. Sleeping on your back is a good alternative if you do not snore and have no sleep apnea. Stomach sleeping is the position most often linked to back and neck strain. That said, the research on sleep posture is thinner than most websites suggest, so the honest answer depends on your specific problem: back pain, snoring, reflux or pregnancy.

This guide goes through each position, what the evidence says for each common issue, and how to change position if you need to.

The best sleeping position at a glance

What the research says about sleep posture and pain

There is less evidence on this than you might expect. A scoping review in BMJ Open screened 4,186 articles on sleep posture and spinal symptoms and found only four relevant studies ¹. Side lying was generally protective against waking pain and stiffness, but the authors concluded there were not enough high-quality studies to answer the question properly ¹.

A 2025 systematic review of six observational studies on low back pain found that back sleeping was associated with lower back pain prevalence, stomach sleeping with higher risk, and side lying with less pain when spinal alignment was supportive and more pain when it was not ². Observational studies cannot prove cause. People with back pain may also choose different positions because of their pain.

The consistent thread is alignment. A position that keeps your spine near neutral and avoids twisting seems better than one that holds your lower back arched or rotated for hours. If back pain is your main concern, read our dedicated guide on sleeping with lower back pain.

Sleeping on your side

Side sleeping is the most common adult position ². For most people it is a safe default.

Pros

• Associated with less waking spinal pain when alignment is good ¹².
• Reduces airway collapse compared with lying on your back, which helps with snoring and positional sleep apnea ³.
• Left side lowers nighttime reflux (see below) ⁵⁶.
• Recommended in late pregnancy ⁷.

Cons

• Can load the shoulder underneath you, which matters for swimmers, climbers and anyone with a shoulder injury.
• A pillow that is too high or too low bends the neck sideways.
• Twisting the top leg forward rotates the lower back.

How to do it well

• Use a pillow that fills the gap between your ear and the mattress so your head stays level. Our guide to the best pillow for side sleepers covers height and loft.
• Put a pillow between your knees to keep your hips stacked.
• Choose a mattress that lets your shoulder and hip sink in a little. See mattresses for side sleepers.

Sleeping on your back

Sleeping on your back spreads your weight evenly and keeps the spine in a neutral line.

Pros

• Associated with lower back pain prevalence in observational studies ².
• Easy on the shoulders.

Cons

• Worst position for snoring and sleep apnea in many people. In positional sleep apnea, breathing pauses happen mainly when you lie on your back. How common that pattern is depends heavily on which definition you use: in one study of over 400 patients, estimates for older adults ranged from about 20% to 49% depending on the classification system ³.
• Not advised for going to sleep in late pregnancy ⁷.

How to do it well

• A thin to medium pillow that supports the curve of your neck.
• A small pillow under your knees can ease the lower back.
• If you snore, try side sleeping or raising the head of the bed. A systematic review noted that head-of-bed elevation may improve sleep apnea symptoms ⁴. An adjustable bed is one way to do that, though a wedge also works.

Sleeping on your stomach

Stomach sleeping is the position most consistently linked to back pain ². To breathe, you have to turn your head fully to one side for hours, and a soft mattress lets your hips sink, which arches the lower back.

If you cannot sleep any other way:

• Use a very thin pillow or none under your head.
• Put a thin pillow under your hips to reduce the arch.
• Try a half-side position, with one knee bent and a pillow under that side of your chest.

Best position for reflux and heartburn

Here the evidence is better. In a small study of 10 patients with reflux disease, lying on the right side was linked to more time with acid in the esophagus and slower acid clearance than the left side, back or stomach ⁵.

A double-blind randomized trial of 100 patients with nighttime reflux then tested a wearable that vibrated whenever the wearer rolled onto the right side ⁶. Treatment success, defined as at least a 50% reduction in nighttime reflux symptoms, was 44% with the active device versus 24% with sham ⁶. Time on the left side rose from about 39% to 61%, and patients had more reflux-free nights ⁶.

So if you have heartburn at night, sleep on your left side. Avoid large meals and alcohol late in the evening as well.

Best position in pregnancy

From 28 weeks of pregnancy, the position you settle into at the start of the night matters. An individual participant data meta-analysis of five case-control studies (851 stillbirths, 2,257 controls) found that going to sleep on the back was linked to about 2.6 times higher odds of late stillbirth compared with the left side ⁷. Going to sleep on the right side had similar odds to the left ⁷. Either side appears equally safe.

If you wake on your back, do not panic. Roll onto your side and go back to sleep. This is a reason to talk with your midwife or doctor, not a reason to lose sleep worrying.

For people who train

• Shoulder load: side sleeping on an injured or sore shoulder can delay settling. Sleep on the other side, or on your back with a pillow hugged to your chest.
• Hip and IT band soreness after long runs: a pillow between the knees reduces pressure on the top hip.
• Snoring on some nights: if you notice you snore more after alcohol or long travel days, start those nights on your side. Loud snoring with gasping deserves a medical check.
• Race week: do not experiment with a new position, pillow or mattress. Changes can disturb sleep for several nights while you adapt.

How to change your sleeping position

Changing habits takes a few weeks.

1. Start the night in the new position. You will move during the night anyway.
2. Use pillows as barriers. A body pillow behind your back makes it harder to roll onto it.
3. Try the "tennis ball" trick for back sleeping. A ball in a pocket sewn to the back of a shirt makes back lying uncomfortable. Commercial positional devices work on the same idea ⁶.
4. Fix the setup. Many people sleep on their stomach because their pillow is too high for side sleeping. A better pillow often solves the habit.

Common mistakes

• Believing there is one perfect position. The research does not support that ¹.
• Ignoring the pillow. Height matters as much as position. See our guide to pillows for neck pain.
• Changing everything at once. New mattress, new pillow and new position in one week makes it hard to know what helped.
• Treating snoring as harmless. Positional changes help some people with sleep apnea, but loud snoring with daytime sleepiness needs a medical assessment.

The bottom line

For most people, side sleeping with good alignment is the safest default. Back sleeping works if you do not snore. Stomach sleeping is the one to move away from if you have back or neck pain. The left side helps with reflux, and from 28 weeks of pregnancy you should go to sleep on either side. Since bodies vary and the evidence is limited, pick the position that keeps your spine neutral and lets you sleep through the night.

Frequently asked questions

Is it better to sleep on your left or right side?

For most people either side is fine. If you have nighttime heartburn, the left side is better: studies found more acid exposure on the right side, and a randomized trial showed that a device that discouraged right-side sleeping improved reflux symptoms. In late pregnancy, going to sleep on either side carries similar risk, and both are safer than going to sleep on your back.

Is sleeping on your back good for you?

Back sleeping keeps the spine neutral and was associated with lower back pain prevalence in observational studies. It is the worst position for many people who snore or have sleep apnea, because the airway collapses more easily when you lie flat. It is also not advised for going to sleep after 28 weeks of pregnancy. If you do not snore, it is a good choice.

Why is sleeping on your stomach bad?

Stomach sleeping forces you to turn your head fully to one side for hours, which strains the neck, and it can arch your lower back, especially on a soft mattress. Observational studies link it to higher back pain risk. If you cannot sleep any other way, use a very thin pillow and put a thin pillow under your hips.

What is the healthiest sleeping position?

There is no single healthiest position for everyone. Side sleeping with good alignment is the best general choice and helps with snoring and reflux. Back sleeping is good for people who do not snore. The research is limited and mostly observational, so the best position for you is one that keeps your spine near neutral and lets you sleep through the night.

Can changing sleep position help with snoring?

Often, yes. Many people snore more or have more breathing pauses when lying on their back. Sleeping on your side or raising the head of the bed can reduce this. Loud snoring with gasping, breathing pauses or daytime sleepiness can be a sign of sleep apnea, which needs a medical assessment rather than position changes alone.

Sources

1. Cary D, Briffa K, McKenna L (2019). Identifying relationships between sleep posture and non-specific spinal symptoms in adults: A scoping review. BMJ Open.
2. Saini Y, Rai A, Sen S (2025). Relationship Between Sleep Posture and Low Back Pain: A Systematic Review. Musculoskeletal Care.
3. Iannella G et al. (2020). Positional Obstructive Sleep Apnea Syndrome in Elderly Patients. International Journal of Environmental Research and Public Health.
4. Pham T et al. (2020). Obstructive sleep apnea's association with the cervical spine abnormalities, posture, and pain: a systematic review. Sleep Medicine.
5. Khoury RM et al. (1999). Influence of spontaneous sleep positions on nighttime recumbent reflux in patients with gastroesophageal reflux disease. American Journal of Gastroenterology.
6. Schuitenmaker JM et al. (2022). Sleep Positional Therapy for Nocturnal Gastroesophageal Reflux: A Double-Blind, Randomized, Sham-Controlled Trial. Clinical Gastroenterology and Hepatology.
7. Cronin RS et al. (2019). An Individual Participant Data Meta-analysis of Maternal Going-to-Sleep Position, Interactions with Fetal Vulnerability, and the Risk of Late Stillbirth. EClinicalMedicine.