The position you choose to sleep in each night might be doing more than just helping you get comfortable—it could be influencing your digestion, heart health, brain function, and even your risk for certain conditions. While most people have a favorite side or posture they default to, science suggests that the side you sleep on could have meaningful health impacts, both positive and negative.
One of the most well-researched benefits of side sleeping, particularly on the left side, relates to digestion and gut health. According to a review published in the Journal of Clinical Gastroenterology, sleeping on your left side may improve the efficiency of your digestive system. This is largely due to the position of your stomach and pancreas, which sit more naturally on the left side of the body. Left-side sleeping can help food waste move more easily through the intestines, reduce acid reflux, and support smoother nutrient absorption. For people suffering from conditions like gastroesophageal reflux disease (GERD), this sleep position may offer tangible relief.
There are also implications for cardiovascular health. The heart sits slightly on the left side of the chest, and some studies suggest that sleeping on the right side may reduce pressure on the heart. A small study published in The American Journal of Cardiology found that heart failure patients often avoid sleeping on their left side, potentially due to discomfort or the perception of added cardiac strain. Conversely, right-side sleeping may promote better blood flow and stabilize heart rate in certain individuals, although more research is needed to confirm these findings across broader populations.
Sleep position may even impact your brain’s ability to cleanse itself during the night. Research published in The Journal of Neuroscience explored how the brain’s glymphatic system—which clears waste products and toxins—may function more efficiently when a person sleeps on their side, as opposed to on their back or stomach. This waste-clearing process has been linked to lower risks of neurodegenerative diseases like Alzheimer’s, making side sleeping potentially protective for long-term brain health.
Back sleeping, while sometimes beneficial for spinal alignment, has its downsides. It can worsen snoring and obstructive sleep apnea by allowing the tongue to fall back into the airway. For individuals already prone to these conditions, side sleeping is often recommended to promote better airflow and reduce nighttime interruptions. Meanwhile, stomach sleeping is generally discouraged by experts because it can place undue stress on the neck and lower back, potentially leading to pain and stiffness upon waking.
Despite the health considerations, the “best” sleep position can vary depending on personal health factors. Pregnant individuals, for instance, are typically advised to sleep on their left side to optimize blood flow to the fetus. People with shoulder injuries might favor the opposite side to avoid discomfort. What’s most important is finding a position that minimizes pain, supports good posture, and doesn't exacerbate any existing medical conditions.
Adjusting your sleep position can take time, especially if your body is accustomed to a certain posture. To ease the transition, sleep experts suggest using pillows to support your back or between your knees, depending on the direction you're trying to shift. Small ergonomic changes like these can help your body adapt and allow you to benefit from a healthier sleeping habit over time.
Disclaimer: This blog post is for informational purposes only and should not be taken as medical advice. Always consult with a healthcare provider for guidance tailored to your individual health needs and concerns.
References
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Khazaie, H., et al. (2015). “The Effects of Body Position on Sleep.” Sleep Science
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Tsai, M.C., et al. (2013). “The Effect of Bed Head Elevation on Acid Exposure Time and the Symptoms of Nocturnal Gastroesophageal Reflux.” Journal of Clinical Gastroenterology
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Lee, H., et al. (2015). “The Effect of Body Posture on Brain Glymphatic Transport.” The Journal of Neuroscience
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National Sleep Foundation. “Sleep Positions: What’s Best?” [sleepfoundation.org]