Sleeping on Left Side vs Right Side: What’s the Best for You?

Everyone sleeps, but you may not be getting all the health benefits it offers.

Many factors affect the depth and success of your sleep cycle—the food you eat, how much time you’ve spent outside, your exercise routine, and your sleeping position.

No matter if you sleep on your left or right side, stomach, or back—there’s a lot of info out there about the best sleeping position. We’ll cover why sleeping position matters, especially when it comes to your heart health.

Who Should Sleep on Their Left Side?

Sleeping on the left side benefits various individuals by improving digestion, circulation, and overall health.

• People with Acid Reflux or GERD: Helps prevent stomach acid from flowing back into the esophagus, reducing heartburn and discomfort.
• Pregnant Women: Enhances blood flow to the baby, reduces pressure on organs, and minimizes swelling.
• Those with Heart Disease or High Blood Pressure: Supports better circulation and reduces strain on the heart.
• Individuals with Digestive Issues: Aids digestion by allowing food to move smoothly through the intestines.
• People Seeking Better Lymphatic Drainage: Enhances toxin removal and reduces fluid retention.
• Snorers or Those with Mild Sleep Apnea: Keeps the airway open, reducing snoring and breathing issues.

Who Should Sleep on Their Right Side?

Sleeping on the right side meaning it can be beneficial for certain individuals, depending on their health needs and comfort preferences.

• People with Heart Failure: Some individuals with heart conditions may feel less strain on the heart when sleeping on the right side.
• Those Who Experience Discomfort on the Left Side: If left-side sleeping causes bloating, stomach pressure, or discomfort, switching to the right side may help.
• Individuals with Liver or Pancreatic Issues: Reduces pressure on these organs, making it a more comfortable position for some people.
• Snorers and Those with Sleep Apnea: Helps keep the airway open, reducing snoring and mild breathing interruptions.

Sleep Position Matters

The best sleep position for you does more than help you get comfortable; it can lead to or prevent certain sleep disorders. Stomach sleepers, for example, are more prone to lower back pain and shoulder pain due to the increased pressure on their lower spine.

If you currently deal with lower back pain and you sleep on your stomach, look for a firmer mattress that prevents the pelvis from sinking into the mattress’s surface.

We typically don’t recommend stomach-sleeping at all because of the pain risk it carries.

Back sleeping, on the other hand, is the position that most readily keeps the spine in a neutral position and prevents neck pain. A neutral spine is relatively straight and level from the top of the head down to the pelvis.

A neutral spine, no matter the sleeping position, should always be your goal.

The neutrality of back sleeping can change based on your weight and mattress type. For example, if you have a mattress that’s too firm for your body weight, the mattress may not conform to the shoulders and hips. That can put pressure on the spine and force it out of alignment rather than supporting the curves of the upper and lower back.

As good as back sleeping is for spinal alignment, it isn’t the best position for every medical condition. For example, gastroesophageal reflux disease (GERD) can be worse when back sleeping.

In this position, gravity doesn’t keep stomach acid in the stomach. Additionally, nighttime acid reflux can do more damage to the esophagus because there’s less saliva production and swallowing, which limit acid in the esophagus during the day.

The sleeping position that’s best for you depends on a combination of your medical conditions and your personal preferences. You can keep your spine neutral in almost any position as long as you have the best mattress for your sleep style.

We’ve already mentioned how firmer mattresses can help stomach sleepers, but side sleepers have unique needs too. Back sleepers generally enjoy the most mattress options because of their naturally neutral spinal position. For them, personal preference gets to play a bigger role.

We’ve spent a lot of time on stomach and back sleeping, but what about side sleeping? As the most common sleep position and the healthiest for the heart, it deserves special attention.

The Benefits of Side Sleeping

When it comes to the heart, side sleeping wins out because it decreases the risk of acid reflux, snoring, and it’s best for the heart. Side sleeping is the most common sleeping position among humans and animals. This one position has three basic variations:

• Fetal Position: As the name suggests, this position mimics the position of a fetus— the knees tucked towards the chest with the hands pulled in. The slight curve of the spine in this position relieves pressure and stress on the back.
• Yearner Position: The yearner sleepers on one side with the legs straight and arms extended straight forward as though reaching for someone.
• Log Position: The log sleeper lies on their side with legs relatively straight and arms straight at the sides.

While these are the most common side positions, many people are combo sleepers who switch to a different side or even back or stomach position during the night. The best mattress for side sleepers cushions and supports the curves of the body evenly. They need pressure relief at the shoulders and hips with plenty of support for the head and feet.

Side sleeping has some interesting health benefits. During the day, your brain creates waste proteins. These proteins build up and clog the tiny interstitial spaces in the brain.

While you sleep, the glymphatic system removes these toxic proteins. The cleansing process causes brain cells to shrink, which opens those tiny spaces so spinal fluid can flush through. This system works 24 hours a day, but it’s 90 percent more active while you’re asleep.

A 2015 study found that side sleeping increases the efficiency and activity of the glymphatic system. Researchers used MRI images to view what happens in different sleep positions. And, of the main three positions, the side sleeping had the greatest impact on brain cleansing.

Scientists believe that a slow down in this cleansing process could contribute to Alzheimer’s disease. Therefore, a sleeping position that allows this process to work freely is best for brain health.

Your sleeping position can lead to sleeping disorders, as well. Sleep apnea, more specifically obstructive sleep apnea, is a sleeping disorder in which breathing periodically stops throughout the night. People with this condition stop breathing hundreds of times during their sleep cycle, which causes a drop in oxygen levels.

These breathing episodes also cause them to briefly wake up over and over again during the night. If you have sleep apnea, you may be in bed for a full seven hours, but still wake up exhausted.

Side Sleeping for a Healthier Heart

Side sleeping creates the right conditions for optimal heart health too, but both sides aren’t equal. Sleeping on the left side isn’t necessarily bad for your health, it’s just not as healthy as sleeping on the right side.

Lying on the right side creates more space in the chest cavity and reduces pressure on the heart muscles. Imagine the chest cavity with the heart on the left side. If you lie on your right side, gravity pulls the heart into the chest cavity rather than against the wall of the rib cage. That puts less pressure on it and reduces its nighttime workload. If you’re already suffering from a heart condition like heart disease, that extra work can take its toll.

The question of heart health was at the center of a 2016 study among patients with congestive heart failure (CHF). Researchers noticed that people with CHF consistently reported discomfort when they slept on their left sides.

They consciously chose their right sides over the left side to reduce their discomfort.

The same pattern was not observed in a control group in which there were no patients with CHF. More importantly, those who avoided sleeping on the left side had improved heart test results at the end of the study.

Heavy snoring is a common symptom of sleep apnea, and side sleeping can help. It improves oxygen levels because it reduces the breathing episodes related to sleep apnea.

In a study conducted amongst overweight sleepers, it was found that side sleeping improved oxygen levels by six to seven percent. The benefits went down the heavier the sleeper, but it still made a significant difference in their sleep health.

Benefits of Sleeping on Your Left Side

1. Improves Digestion

The digestive system is heavily influenced by body positioning, and sleeping on the left side can significantly aid digestion.

The stomach and pancreas are both located on the left side of the body, and this position allows gravity to assist in the natural movement of food and digestive juices through the intestines.

As a result, it can help prevent common digestive issues such as bloating, constipation, and acid reflux. Additionally, left-side sleeping supports more efficient elimination of waste through the colon, promoting regular bowel movements and reducing discomfort caused by indigestion.

2. Reduces Acid Reflux & Heartburn

People who suffer from acid reflux or heartburn can benefit from sleeping on their left side, as this position helps prevent stomach acid from flowing back into the esophagus.

When lying on the left side, the stomach remains below the esophageal sphincter, which acts as a natural barrier to acid reflux.

This reduces the chances of experiencing burning sensations, discomfort, and nighttime regurgitation that are common with gastroesophageal reflux disease (GERD).

In contrast, sleeping on the right side can worsen acid reflux symptoms by allowing acid to travel more freely up the esophagus, leading to increased discomfort.

3. Boosts Heart Health

Sleeping on the left side is beneficial for heart health, as it improves circulation and reduces pressure on the heart. Since the heart is naturally positioned on the left side of the body, lying in this position allows it to pump blood more efficiently throughout the body.

This can be particularly advantageous for people with high blood pressure, as it minimizes strain on the heart and enhances overall cardiovascular function.

Improved circulation also reduces the risk of fluid retention in the lower extremities, preventing swelling in the legs and feet. Additionally, left-side sleeping may lower the risk of developing heart-related complications over time.

4. Supports Lymphatic Drainage

The lymphatic system plays a vital role in removing toxins, waste, and excess fluids from the body. Because the majority of the lymphatic system drains toward the left side, sleeping in this position facilitates more effective waste elimination.

This can help reduce inflammation, improve immune function, and support overall health by allowing the body to detoxify more efficiently. Proper lymphatic drainage also contributes to reducing puffiness, bloating, and fluid retention, particularly in individuals who experience swelling in the limbs.

5. Recommended for Pregnancy

Pregnant women are frequently advised to sleep on their left side due to its numerous benefits for both mother and baby. This position enhances blood flow to the placenta, ensuring a steady supply of oxygen and essential nutrients to the developing fetus.

It also relieves pressure on major organs such as the liver and kidneys, which can improve kidney function and reduce swelling in the legs, ankles, and feet.

Additionally, sleeping on the left side helps prevent compression of the inferior vena cava, a large vein responsible for returning blood from the lower body to the heart. This can lower the risk of dizziness, shortness of breath, and circulatory problems during pregnancy, making it a recommended sleep position for expectant mothers.

Drawbacks of Sleeping on Your Left Side

1. Increases Pressure on the Heart

Although sleeping on the left side is generally beneficial for circulation, some individuals, particularly those with existing heart conditions, may feel discomfort due to increased pressure on the heart. This can cause a sensation of heaviness or unease, leading some people to prefer sleeping on their right side instead.

People with congestive heart failure, in particular, may find it uncomfortable to sleep on the left side, as it can alter heart function and breathing patterns. In such cases, consulting a doctor for personalized sleep recommendations is advisable.

2. Shoulder & Arm Numbness

One common drawback of sleeping on one side for an extended period is the risk of numbness, tingling, or discomfort in the shoulder and arm. When weight is concentrated on one side, it can compress nerves and restrict blood flow, leading to temporary numbness or pain.

Over time, this can contribute to shoulder stiffness or even nerve-related issues such as tingling sensations (paresthesia). To mitigate this, individuals can try alternating sides or using a supportive pillow to reduce pressure on the shoulder and arm.

3. Not Ideal for People with Heart Failure

Some studies suggest that individuals with congestive heart failure may find it uncomfortable to sleep on their left side. This is because the position can increase the strain on the heart, potentially making it harder for the heart to pump efficiently.

Many people with heart failure tend to prefer sleeping on their right side to alleviate discomfort and reduce the sensation of breathlessness. Anyone with a pre-existing heart condition should discuss their sleep position with a healthcare provider to determine the best option for their specific needs.

Benefits of Right-side sleeping

Right-side sleeping has also been shown to benefit the sympathetic nervous system. That’s the part of your nervous system that controls your fight or flight response. That also means it influences your heart rate and blood pressure.

The pressure relief of right-side sleeping regulates blood flow, which stabilizes the heart rate and blood pressure. Whether you’re suffering from a heart condition or not, a stable heart rate and blood pressure can help you sleep and improve overall health.

Sleeping on the right side can be beneficial for individuals who suffer from obstructive sleep apnea or habitual snoring. When lying on the back, gravity causes the tongue and soft tissues in the throat to collapse backward, partially blocking the airway and leading to breathing interruptions.

Right-side sleeping, like left-side sleeping, helps keep the airway open, reducing the likelihood of airway obstruction and promoting smoother breathing throughout the night. While left-side sleeping is often recommended for conditions like acid reflux and heart health, some people with sleep apnea find that right-side sleeping provides greater comfort and allows for easier breathing.

This can lead to fewer nighttime awakenings, improved oxygen flow, and a more restful sleep overall. However, the best sleeping position for sleep apnea varies from person to person, and in severe cases, medical interventions like continuous positive airway pressure (CPAP) therapy may be necessary.

Unlike sleeping on the left side, which can put pressure on organs like the stomach, pancreas, and liver, sleeping on the right side may alleviate discomfort for some individuals.

When lying on the left side, the stomach and pancreas are compressed, which can sometimes contribute to feelings of bloating or digestive discomfort. By switching to the right side, some people may experience relief from these sensations, particularly if they have conditions such as gastritis or liver congestion.

Additionally, individuals with certain medical conditions, such as an enlarged liver or gallbladder issues, may find that right-side sleeping feels more comfortable by reducing pressure on these organs.

However, for those with acid reflux, right-side sleeping may worsen symptoms, as it allows stomach acid to move more easily into the esophagus. Ultimately, the best sleep position depends on an individual’s specific health concerns and comfort preferences.

Drawbacks of Sleeping on Your Right Side

1. May Worsen Acid Reflux & Heartburn

For individuals prone to acid reflux or gastroesophageal reflux disease (GERD), sleeping on the right side may exacerbate symptoms. This is because the lower esophageal sphincter, the muscle responsible for keeping stomach acid from rising into the esophagus, tends to relax more in this position. As a result, stomach acid can flow back up, leading to uncomfortable symptoms such as heartburn, regurgitation, and throat irritation.

Studies have shown that left-side sleeping helps keep the stomach positioned below the esophagus, reducing acid reflux. However, if right-side sleeping feels more comfortable, individuals with acid reflux may need to take additional precautions, such as using an elevated pillow or adjusting their diet before bedtime to minimize symptoms.

2. Less Effective for Digestion

Compared to left-side sleeping, right-side sleeping does not promote digestion as efficiently. The stomach and pancreas are both positioned on the left side of the body, and gravity naturally aids in the movement of food through the digestive tract when lying on the left side. Sleeping on the right side, on the other hand, can slow down digestion and make it more difficult for the body to process food effectively.

This may lead to bloating, indigestion, or constipation in some individuals. People with digestive concerns or conditions like irritable bowel syndrome (IBS) may find that left-side sleeping provides more relief and supports better gut health.

3. Could Restrict Blood Flow to the Heart

Some research suggests that sleeping on the right side may slightly reduce blood flow to the heart. Since the heart is positioned slightly to the left in the chest cavity, lying on the right side may cause a subtle shift in circulation, potentially making it more challenging for the heart to pump efficiently.

While this effect is typically minor and does not pose significant risks for healthy individuals, people with existing heart conditions may find that left-side sleeping feels better in terms of circulation and overall comfort.

However, for some individuals with heart failure, sleeping on the right side is actually recommended to alleviate pressure on the heart. The impact of right-side sleeping on heart health varies from person to person, so individuals with cardiovascular concerns should consult their doctor for personalized advice on the best sleep position.

Making the Change to the Right Side

If sleeping on your side isn’t your preferred sleeping position, take heart. As children, we spend almost equal time among the three sleeping positions. By the teen years, the side position starts to take the lead. By age 45, most people prefer the side over any other common sleep position.

You can train your body to sleep differently. Bolsters and pillows are the easiest way to make the change. Regular or body pillows tucked behind your back can help keep you on the right side. You can also try sleeping on a couch or in a day bed, where a backrest supports the back and keeps you in the right position. Keep in mind that your position preferences can change over time. You may need to revisit your training after a few months or years.

As you age, the benefits of right-side sleeping increase. Aches, shoulder pain, and medical conditions have a bigger influence on your nighttime comfort. Age reduces the number of times you switch positions. Therefore, you’re more likely to end in the position in which you started. That’s a good thing for your heart health.

We do want to mention the exception to right-side sleeping, and that is pregnant women. In these cases, sleeping on the left side increases blood flow to the fetus. Obviously, stomach sleeping is out, and back sleeping can put too much pressure on the spine. For pregnant women, sleeping on the left side is the healthiest option.

FAQs

What is the healthiest way to sleep?

The healthiest way to sleep depends on individual needs, but side sleeping is often recommended for spinal alignment and overall comfort. It reduces snoring, which can improve breathing, and may also help with digestion by preventing acid reflux. A supportive pillow and mattress can further enhance sleep quality and prevent aches.

How does sleeping on your side benefit your health?

Sleeping on your side can improve airflow, making it beneficial for those with sleep apnea or snoring issues. It also helps with digestion by preventing acid reflux and promoting better gut function. Additionally, this position reduces pressure on the spine and joints, leading to a more comfortable and restful sleep.

Why is the left side better for sleeping?

Sleeping on the left side is often recommended because it enhances digestion by allowing gravity to aid in the movement of food through the intestines. It also improves circulation by reducing pressure on the heart, which can be particularly beneficial for those with high blood pressure. Additionally, it helps minimize acid reflux and heartburn, making it a preferred position for many people.

What is the best sleeping position during pregnancy?

Pregnant individuals are advised to sleep on their left side because it improves blood flow to the placenta, ensuring the baby gets enough oxygen and nutrients. This position also helps reduce swelling in the hands and feet by promoting better circulation. Additionally, it relieves pressure on the lower back and prevents discomfort, making sleep more restful.

How can you prevent hip pain when sleeping on your side?

To prevent hip pain, placing a firm pillow between your knees can help align the hips and relieve pressure. A supportive mattress that contours to your body can also reduce discomfort and prevent misalignment. Stretching before bed and adjusting sleeping posture can further minimize strain on the hips.

What can you do to relieve shoulder pain from side sleeping?

Using a high-quality pillow that supports your neck and shoulders can prevent strain and reduce discomfort. It also helps to switch sides occasionally to avoid putting prolonged pressure on one shoulder. Additionally, gentle shoulder stretches before bed and in the morning can improve flexibility and reduce stiffness.

Where should your arms be when sleeping on your side?

Keeping your arms in a neutral position, such as resting in front of your body or hugging a pillow, can help prevent numbness and strain. Avoid placing your arms under your head or body, as this can compress nerves and lead to discomfort. If needed, using a body pillow for additional support can help maintain proper alignment and prevent awkward arm positioning.

A Final Word

If you’re at risk for heart issues, sleeping on the right side could have long-term benefits. If you’re older, you may already find yourself gravitating to the right— but when you make a conscious choice, choose the right side.

Make sure you’ve got a mattress that supports your sleeping position—one that conforms and cushions your shoulders and hips, will keep the spine aligned, and maintain comfort all night long. If you can start the night out right, your heart with thank you.