It may be particularly useful for people who snore or experience certain forms of sleep-disordered breathing.
When you sleep on your side, gravity may be less likely to allow the tongue and soft tissues of the throat to fall backward and obstruct the airway.
This is one reason side sleeping is commonly discussed in relation to obstructive sleep apnea.
But side sleeping can have other advantages as well.
People who experience acid reflux may find that sleeping on the left side is more comfortable.
Research and clinical guidance suggest that left-side sleeping can reduce nighttime reflux symptoms for some people because of the anatomical relationship between the stomach and esophagus.
Pregnancy is another situation in which sleeping position receives special attention.
As pregnancy progresses, many people find side sleeping more comfortable, and healthcare professionals may provide individualized recommendations depending on the stage of pregnancy and the person's health.
However, side sleeping is not perfect.
Some people develop shoulder discomfort because one shoulder supports much of the body's weight for hours.
Others may experience hip pain, numbness, or pressure points.
The pillow also matters.
A pillow that is too high or too low can place the neck in an uncomfortable position.
For side sleepers, a pillow should generally provide enough support to keep the head and neck reasonably aligned with the spine.
A pillow between the knees may also make side sleeping more comfortable for some people, particularly those with certain types of hip or lower-back discomfort.
The key idea is that there is no single perfect sleeping position for everyone.
Your ideal position depends on your anatomy, health conditions, mattress, pillow, age, pregnancy status, and individual comfort.
Rather than becoming frightened by a social-media claim, pay attention to what happens during your sleep.
Do you wake with shoulder pain?
Do you regularly experience heartburn?
Do you snore loudly?
Do you wake choking or gasping?
Do you feel exhausted even after a full night's sleep?
These questions are much more useful than simply asking whether you sleep on your back or side.
If changing position improves symptoms, that can be helpful information—but persistent symptoms should still be discussed with a healthcare professional.
Image 2 — Suggested placement:
A realistic standalone photograph of a European woman sleeping comfortably on her side with appropriate pillow support between her knees. Bright, natural bedroom, no text, logo, watermark, or medical illustration.