Sleeping on the left side may benefit people with GERD, but it may have negative effects on the heart. However, more research is needed to support these theories.

The positions you sleep in at night may affect your health.

For example, sleeping face-up with a pillow under your back may help with back pain, but it may also worsen symptoms of sleep apnea. Sleeping on your side may be better for sleep apnea, but you may find that it hurts your spine.

If you’re living with a heart condition, you may want to avoid sleeping on your left side as it may increase pressure on the heart. However, more research is needed on this subject.

That said, researchers have found that not getting enough sleep or getting poor quality sleep raises your risk of developing heart disease and other illnesses. So most doctors agree that the best sleeping position for you is the one that’s most comfortable for you.

Keep reading to learn more about the potential health benefits of left- and right-sided sleeping.

Sleeping on your left side may help people who experience acid reflux and gastroesophageal reflux disease (GERD). A 2022 study found that sleeping on your left side was associated with significantly shorter acid exposure and faster esophageal clearance than sleeping on your right side.

There’s also some evidence that sleeping on your left side may have some negative effects on the heart.

In 1997, researchers first noticed that side-sleeping caused noticeable changes to the electrical activity of the heart measured with an electrocardiogram (ECG). The researchers found a more noticeable effect when the participants were lying on their left side.

In a more recent 2018 study, researchers also found that sleeping on the left side was associated with changes in ECG readings in healthy participants. Using a type of imaging technique called vectorcardiography, they found that left-side sleeping caused the heart to shift and turn.

When the participants slept on their right side, almost no change in ECG activity was found. The researchers found that in this position, the heart was held in place by the thin layer of tissue between the lungs called the mediastinum.

Researchers attributed the changes in electrical activity to the re-positioning of the heart. However, it’s worth noting that sleeping on the left side did not affect the heart’s electrical function but rather the collection of data.

More research needs to be done to understand if sleeping on your left side is dangerous for people with heart conditions or how dangerous it may be.

There remains some controversy about whether sleeping on your left or right side is better for your heart. Some sleep experts think that sleeping on your right side could compress your vena cava. This is the vein that feeds into the right side of your heart.

However, at this time, there’s no evidence that sleeping on your right side increases your risk of developing heart failure, and it seems to be safe.

A 2018 study found that the majority of participants with a heart muscle disease called consecutive dilated cardiomyopathy preferred to sleep on their right side rather than their left.

Also, a 2019 review of studies found no difference in the health of pregnant people or their unborn babies when sleeping on their left or right sides. However, lying on your side with your knees bent is likely to be the most comfortable position as your pregnancy progresses. You can experiment with using a body or wedge pillow between your knees for added comfort.

Some doctors recommend that pregnant people sleep on their left side. This is because your liver is on the right side of your abdomen, and lying on your left side helps keep the uterus off that large organ.

That said, lying on your right side when pregnant makes your heart’s job easier because it keeps the fetus’ weight from applying pressure to the large vein (called the inferior vena cava) that carries blood back to the heart from your feet and legs to improve blood flow to the fetus.

What are the best sleeping positions for your heart?

At this time, it’s still not clear what the best sleeping position is for your heart health if you don’t already have an underlying heart condition. Likely, getting quality sleep is more important than your sleeping position.

A 2018 review of studies published in the Journal of Clinical Sleep Medicine found that both poor sleep quality and short sleep duration are associated with a risk of coronary heart disease.

If you’ve had heart failure, you should speak with your doctor about sleeping positions to avoid.

Sleeping on your right side may be the best option for people with heart failure. Although some people think sleeping on your right side could restrict blood flow back to the heart, there’s not enough evidence to prove that it’s harmful.

If you don’t have sleep apnea or breathing problems, sleeping on your back may also be an option.

A 2015 study examined the effects of lying face-up in participants with stable chronic heart failure. The researchers found that lying face up was associated with poorer blood oxygenation, respiratory mechanics, and blood movement compared to sitting.

Sleeping on your stomach may alleviate sleep apnea and snoring but can also cause neck or back pain. Untreated sleep apnea is associated with an increased risk of heart failure, and many people deal with both.

If you have an implantable cardioverter defibrillator (ICD), you may find it more comfortable to sleep on the opposite side that it’s implanted. Most ICDs are located on the left side.

Anecdotally, some people have reported that sleeping with a wedge behind them or on a recliner helps with nighttime breathing.

If you’re experiencing shortness of breath when lying flat, talk with a doctor. If you’re retaining fluid following an ICD placement, you may need treatment.

At this time, it’s still unclear what the best way to sleep is for your heart and overall health.

Anecdotally, many people with heart failure seem to find it more comfortable to sleep on their right side than on their left side. However, there’s very little scientific data that supports one way of sleeping over another

Research has confirmed that not getting enough sleep or getting poor quality sleep raises your risk of developing heart disease and other illnesses.

Making sure you stay well-rested is important for maintaining optimal heart health, no matter the position in which you sleep.