Skip to content 
A good night’s sleep affects far more than how energetic you feel the next morning.
Sleep supports concentration, mood, immune function and many other aspects of health.
But there is another question people often ask.
Does the position you sleep in matter too?
Sometimes, yes.
Yet the real answer is more nuanced than many viral health posts suggest.
Sleeping on the left side may be useful for certain people, particularly those who experience nighttime acid reflux.
It can also be comfortable during pregnancy.
But claims that the position somehow “detoxifies” the liver or dramatically improves every major organ go well beyond what medical evidence currently shows.
The most interesting benefits are actually simpler.
And much better supported.
1. Left-Side Sleeping May Reduce Nighttime Acid Reflux
This is the strongest evidence-backed reason to consider sleeping on the left side.
Gastroesophageal reflux happens when stomach contents move upward into the esophagus.
That can cause burning discomfort, a sour taste, coughing or disturbed sleep.
Body position can influence how easily this happens.
Studies comparing sleep positions have found that people with GERD tend to have less nighttime acid exposure and faster acid clearance while lying on the left side than while lying on the right side or flat on the back.
Why?
The anatomy of the stomach and esophagus changes relative to gravity depending on which side is down.
When someone lies on the left, the junction between the stomach and esophagus can sit in a position that makes reflux less likely.
The difference is not merely theoretical.
A randomized trial involving people with nighttime reflux found that encouraging more left-side sleeping improved symptoms and increased the number of reflux-free nights compared with a sham intervention.