There is also no reason to assume that right-side sleeping directly damages the stomach or inevitably causes disease. The potential effect is mainly relevant to people who are susceptible to reflux.
If you regularly experience symptoms after lying down, experimenting with the left-side position may be a reasonable step. Pay attention to whether your symptoms improve, but seek medical advice if they persist or become troublesome.
Chapter 3: Why Sleeping on the Left Side May Help
For people who experience nighttime heartburn, sleeping on the left side may offer a simple way to reduce discomfort.
The stomach lies predominantly on the left side of the upper abdomen. When a person rests on the left, the relationship between the stomach and the esophagus may make it less likely for stomach acid to flow backward.
Research on nighttime reflux has found that left-side positioning can reduce acid exposure and may help the esophagus clear refluxed material more efficiently. However, individual responses vary, and sleeping position is not a substitute for medical treatment when GERD is persistent.