Why Your Gut Wants You to Sleep on Your Left Side Every Night (2024)

Sleeping on your left side offers health benefits, particularly for digestion. Certain tips may help reduce shoulder discomfort.

When we’re pretzeling ourselves into poses at the yoga studio or lifting weights at the gym, we pay close attention to our form to avoid injury and gain the most benefit from the exercise.

The same should go for our slumber.

Our sleep position matters to our health. It affects everything from the brain to the gut. We know that not getting enough sleep can make us feel about as energetic as a sloth. But if you’re logging the recommended seven to eight hours for your adulting needs and still waking up feeling lackluster, you might need to reassess what exactly you’re doing to your body after lights out.

Left-side sleeping has the most expert- and science-backed health benefits. Although our bodies appear largely symmetrical, our organ placement makes us asymmetrical internally. How we rest influences the way our systems direct and process waste — which should be part of our overall health aspirations.

You might track working out, eating a healthy breakfast, or starting the day with a fresh perspective. Why not give your bowel movement the same attention?

For some, a bowel movement happens like clockwork. But others living with irritable bowel syndrome with constipation, lazy bowel syndrome, inflammatory bowel disease, or other gastrointestinal conditions may struggle to check this item off the to-do list. So why not let gravity do the work?

Pro tip for side sleeping

Start out on your left side at night to prevent heartburn and allow gravity to move waste through your colon. Alternate sides if your shoulder bothers you. Place a firm pillow between your knees and hug one to support your spine.

While you sleep on your left side at night, gravity can help take waste on a trip through the ascending colon, then into the transverse colon, and finally dump it into the descending colon — encouraging a trip to the bathroom in the morning.

Side sleeping might also make you a better bedfellow and leave you more well-rested.

“On its surface, snoring could just be seen as annoying, but many people are being diagnosed with sleep apnea,” says Bill Fish, a certified sleep science coach. This means the body actually stops breathing as frequently as 20 to 30 times per hour.”

Pro tips for sleeping on your side

Many of us actually already favor side sleeping. A 2017 study deduced we spend more than half of our time in bed in a side or fetal position. If you’re a side sleeper, you likely do a little flip-flopping during the night. That’s fine. Just try to start out on your left side to pamper your gut.

Directions for side sleeping

“Measure the length between your neck and the end of your shoulder,” Fish says. “Find a pillow that supports this height so that your head and neck can stay aligned with your spine.”

1. Find a pillow that fits your collarbone structure.
2. Place a firm pillow between your knees to stack your hips and support your lower back.
3. Make sure the pillow is firm enough to avoid collapse.
4. Hug a pillow as well so that you have a comfortable place to rest your top arm.
5. Keep your arms parallel to each other and at or below your face.

Shop all Healthline-approved pillows for side sleepers in our sleep shop.

“There are plenty of positives from sleeping on your back,” Fish says. “First off, it is easier to keep your spine aligned.”

In addition, a supine position can take pressure off the shoulder or jaw and reduce tension headaches resulting from those areas.

Sleeping on your back may also reduce discomfort by lessening compression and pain from old injuries or other chronic conditions.

Finding a comfortable position with any chronic pain condition can be a struggle. But starting out on your back with strategic, trial-and-error pillow support might help.

Pro tip for back sleeping

Sleep on a wedge pillow or elevate the head of your bed 6 inches. Lie with legs spread hip-width distance apart and your arms spread in a goalpost formation. Elevate your knees with a pillow.

Side sleeping is the safest choice if you snore or have sleep apnea. But an elevation method could help with these conditions if you prefer sleeping on your back. Talk to your doctor about what’s best for you.

Pro tips for sleeping on your back

“Changing your sleep position isn’t easy, as our bodies have grown accustomed to our sleep ritual for years,” Fish says. “But using a pillow in different ways can help jump-start the change.”

Here are some pro tips to consider:

1. Protect your lower back by tucking a pillow under your knees. This puts your spine in a neutral and supported position.
2. Sleep with legs spread and arms out, like a goalie. This way, you’ll evenly distribute your weight and avoid placing pressure on your joints. This posture has the added benefit of keeping you in place if you’re training yourself to sleep on your back.
3. Try pillows on either side of you to aid as reminders. For your head, choose a pillow that offers support for the natural curve of your neck and keeps your spine in alignment. Fish says the key is to avoid pillow heights that tilt your chin to your chest.
4. Get elevated. For people with heartburn who can’t sleep on their side, use a wedge pillow or elevate the head of your bed 6 inches with bed risers. Elevation can also help prevent sinus buildup for when you have a stuffy nose disrupting your sleep. It can also alleviate facial pressure and headaches.

Stomach sleeping is the big no-no when it comes to slumber poses.

“If you are sleeping on your stomach and notice you are suffering back pain, there probably is a reason,” Fish warns us. “Since the majority of the weight of the human body is around your center, that core pushes into the sleep surface further and basically puts strain on your spine in the wrong direction, causing back and neck pain.”

The only benefit to a downward-facing sleep position is that it may help keep your airways open if you snore or have sleep apnea. However, a side option is better.

Pro tip for stomach sleepers

If you find it hard to minimize stomach sleeping, use a flat pillow or none at all. Tuck a pillow under your pelvis to help relieve pressure.

Shop all Healthline-approved pillows for stomach sleepers in our sleep shop.

Positioning tips for sleeping on your stomach

Always try to avoid sleeping on your stomach. But if you can’t sleep any other way, try to incorporate these tips:

• Alternate the way you turn your head often to avoid neck stiffness.
• Don’t hitch your leg up to one side with a bent knee. That will only wreak more havoc on your back.
• Be careful not to tuck your arms underneath your head and pillow. It could cause arm numbness, tingling, or pain, or anger your shoulder joints.
• Place arms in a goalpost position instead.

All of this talk of sleep has probably made you feel ready for a nap. If you’re about to hop off to bed, remember to be mindful of your form and make adjustments when necessary. You’ll find a position and pillow placement that works for your unique needs before you know it.

If you’re struggling to get all your Zzz’s, try these sleep tips, or browse our sleep shop and discover all the best products for achieving deeper sleep. Chronic insomnia has both long- and short-term consequences on your health, so if you’re staring at the ceiling at night or struggling to get comfortable, reach out to your doctor. They may be able to recommend a sleep study or other helpful interventions.

May the sheep arcing over your head be few and your rest comfy and cozy.

Jennifer Chesak is a Nashville-based freelance book editor and writing instructor. She’s also an adventure travel, fitness, and health writer for several national publications. She earned her Master of Science in journalism from Northwestern’s Medill and is working on her first fiction novel, set in her native state of North Dakota.