Your heart sits slightly to the left of center in your chest.
Your spleen is on the left.
The inferior vena cava (the large vein that returns blood from your lower body to your heart) runs along the right side of your spine.
When you lie on your right side, gravity shifts the position of these organs. For some people, this shift causes problems.
6 Potential Health Effects of Sleeping on Your Right Side
Let me walk you through the most well-documented effects.
1. Worsened Acid Reflux and Heartburn (Most Common)
This is what I experienced. And it’s the most well-studied effect of right-side sleeping.
What happens: Your stomach sits on the left side of your abdomen. When you lie on your right side, your stomach is positioned above your esophagus. Gravity pulls stomach acid toward the lower esophageal sphincter (LES) – the valve that keeps acid from flowing backward into your esophagus. If your LES is weak (as it is in many people with GERD), acid easily leaks out.
