The science: A landmark study published in the American Journal of Gastroenterology found that sleeping on the right side significantly increased acid exposure in the esophagus compared to left-side or back sleeping. Participants had more reflux episodes and longer clearance times.
The comparison:
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Left-side sleeping: Stomach sits below the esophagus. Acid stays put.
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Right-side sleeping: Stomach sits above the esophagus. Acid flows downward toward the LES.
Who is most at risk: People with GERD (gastroesophageal reflux disease), hiatal hernia, frequent heartburn, or anyone who eats large meals close to bedtime.
What you can do: If you have reflux, try sleeping on your left side. Elevate the head of your bed by 6-8 inches (using blocks under the bed frame, not just pillows). Stop eating 2-3 hours before bed.
2. Increased Risk of Gallbladder Discomfort or Attacks
This one surprised me, but the anatomy makes sense.
What happens: Your gallbladder sits on the right side of your abdomen, tucked under your liver. When you lie on your right side, gravity can shift gallstones (if you have them) toward the cystic duct – the narrow passage that drains bile from the gallbladder. If a stone blocks the duct, it can trigger a gallbladder attack: sudden, intense pain in the upper right abdomen, often accompanied by nausea and vomiting.
