We spend about a third of our lives sleeping, and bad or inadequate sleep can have negative effects on health.

For most healthy people, sleeping on either side is unlikely to affect overall health. However, certain sleeping positions may be better for pregnant women and people with specific medical conditions.

Read on to discover the most healthful sleeping positions — in general, during pregnancy, and for people with various medical issues. We conclude with some tips on maintaining the different positions throughout the night.

a couple in bed both sleeping on their sidesShare on Pinterest
Alternating which side you sleep on may help prevent aches and pains.

The National Sleep Foundation report that, overall, sleeping on the back is the best for health, but that only 8 percent of people sleep in this position.

They note that sleeping on the back keeps the neck and spine in a neutral position, which reduces pressure and soreness in these areas.

Sleeping on the back is also the safest position for newborns and infants. Babies who sleep on their backs are less likely to die as a result of sudden infant death syndrome.

However, as we discuss below, sleeping on the back can sometimes put a person’s health at risk.

Pregnant women and people with certain medical conditions may benefit from adopting particular sleeping positions.


In the early stages of pregnancy, it is usually safe to sleep in whichever position feels most comfortable. In the later stages, women may benefit from sleeping on their sides.

Sleeping on the side

During the third trimester of pregnancy, the fetus may be safer if the mother sleeps on her side. Sleeping on the back during this time can put extra pressure on the blood vessels that supply the uterus, resulting in reduced oxygen supply to the fetus.

A 2015 study found a correlation between sleeping on the back and stillbirth. Though the researchers believed that other risk factors were likely responsible, they concluded that sleeping on the back may increase the risk of pregnancy loss among pregnancies that are already high-risk.

However, some experts disagree with these conclusions and argue that the odds of stillbirth remain very low, even among pregnant women who routinely sleep on their backs.

Any pregnant woman who has concerns about her sleeping position should consult a doctor or midwife, who will describe the specific risk factors at play.

Pregnant women who decide to start sleeping on their sides may find that it worsens existing aches and pains. Laying a pillow or two between the knees and keeping the legs bent can help, and a pregnancy body pillow can provide more support.

Sleeping on the left side

Sleeping on the left side during pregnancy can maximize blood flow to the baby and reduce pressure on the liver. This is particularly important in the later stages of pregnancy, especially for women who develop the pregnancy-induced liver disease cholestasis.

A single study also found that sleeping on the left side during the last night of pregnancy reduced the risk of stillbirth. However, subsequent studies have not arrived at this conclusion.

Cold or upper respiratory infection

Symptoms of a cold or upper respiratory infection tend to worsen at night. This is because mucus accumulates in the sinuses and throat when a person lies down. Sleeping with the head elevated can help alleviate associated symptoms, such as a stuffy nose.

Sleeping with the head elevated

Raising the level of the head can help drain the sinuses, preventing nasal blockages and associated headaches. Propping two or more pillows under the head before going to sleep should be effective.

People who have sleep apnea or a tendency to snore should avoid sleeping on their backs, especially when they have a cold. This is because the position may cause the tongue to partially block the flow of air, making breathing difficulties worse. Experiment with various positions to find one that feels comfortable.

Stomach issues

For people with stomach issues, the best side to sleep on may depend on the specific health condition.

Sleeping on the stomach or side

If a person has a stomach virus with frequent vomiting, there is a very small risk of choking on vomit during the night.

To reduce this risk, sleep on the stomach or either side. A person can arrange pillows in a way to prevent themselves from rolling onto their back during the night.

Sleeping on the back or side

Sleeping on the back may be beneficial for people who experience nighttime acid reflux.

In this position, keeping the head elevated may help prevent stomach acid from leaking into the esophagus. The goal is to ensure that the esophagus stays above the level of the stomach.

According to a 2015 study, sleeping on the left side with the head or torso elevated may alleviate symptoms of gastroesophageal reflux. This position may help relax the lower esophagus, preventing it from pushing acid upward.

Cardiovascular conditions

There is little evidence that any sleeping position is best for the heart. However, the American Heart Association (AHA) do report that poor sleep may affect heart health over time.

One condition that can interfere with a good night’s rest is sleep apnea, which involves continual pauses in breathing during sleep.

The AHA note that sleep apnea is associated with an increased risk of cardiovascular problems, such as:

Sleeping on the back can cause the tongue to fall into the back of the throat, obstructing breathing. People who snore or have sleep apnea should, therefore, avoid sleeping on their backs unless a doctor recommends otherwise.

Below, find some strategies designed to help people get comfortable in a new sleeping position and maintain it throughout the night.

Sleeping on the back

Sleeping on the back may bring benefits to many healthy people, though it can take some time to adjust to this position.

When sleeping on the back, it is important to use a thin, firm pillow. Very large, puffy pillows may overly elevate the head, causing the chin to drop into an uncomfortable position.

Some people who go to sleep on their backs roll onto their sides during the night. Keeping pillows propped against either side of the body can help prevent this.

Left vs. right side

For healthy people who are not pregnant, there is no indication that sleeping on one side is more beneficial than another.

Some people find that sleeping on the same side every night puts pressure on certain muscles or otherwise causes discomfort. Alternating sides may help prevent these aches and pains.

A person who sleeps on their side may benefit from placing a pillow between their knees. This can help prevent pressure sores in the area.

Most healthy people are unlikely to benefit from sleeping on either side. However, experimenting with different positions may ultimately help with improving the quality of sleep.

A person has found the right position when they sleep more soundly, wake more easily in the morning, and feel more relaxed and alert throughout the day.

A doctor can help a person with a medical condition determine whether their sleeping position is likely to have any effect. People with sleep apnea, an upper respiratory infection, or gastroesophageal reflux disease are likely to benefit from a change in sleeping position.