A Spanish physician warns that sleeping on your right side could worsen acid reflux and disrupt sleep for those prone to digestive issues, challenging a common bedtime habit many never question
Most people never think twice about which side they sleep on. But according to El Confidencial, Spanish physician Sara Marín is urging patients with nighttime digestive issues to reconsider. Her advice: avoid falling asleep on your right side if you’re prone to acid reflux or heartburn. The reason is anatomical—when you lie on your right, your stomach sits above your esophagus, making it easier for stomach acid to creep upward and trigger symptoms that can ruin your night.
Acid reflux, or gastroesophageal reflux disease (GERD), happens when stomach acid flows back into the esophagus, often after eating. The lower esophageal sphincter, a muscular ring, is supposed to keep acid in the stomach. But gravity plays a role too. On your right side, gravity works against you, letting acid slip past the sphincter more easily. This can mean burning pain behind the breastbone, a sour taste in your mouth, coughing fits, or waking up suddenly in the night. For some, these episodes are rare—maybe after a heavy meal. For others, they’re a nightly battle.
Research backs up the difference your sleep position can make. A 2022 study in the American Journal of Gastroenterology tracked 57 adults with nighttime reflux. Scientists measured how long it took for acid to clear from the esophagus in different positions. The median clearance time was about 35 seconds on the left side, but 90 seconds on the right and 76 seconds lying on your back. The takeaway: left-side sleeping helps gravity keep acid where it belongs, while the right side prolongs exposure and discomfort. The effect is most pronounced in people with GERD, hiatal hernia, or frequent heartburn after dinner.
There are practical ways to reduce nighttime reflux beyond just changing sides. Elevating the head of your bed by six inches can help, as recommended by sleep clinics. Avoid eating large, fatty, or spicy meals close to bedtime, and limit alcohol in the evening. If you struggle to stay on your left side, try wedging a pillow behind your back or placing one between your knees for stability. These small adjustments can make a real difference for those with chronic symptoms.
It’s important to note that sleeping on your right side isn’t dangerous for everyone. Many people without reflux or heartburn sleep this way with no trouble. The key is to pay attention to your own symptoms and patterns. If you notice more discomfort or disrupted sleep after lying on your right, consider switching sides. And if you have persistent reflux, chest pain, trouble swallowing, or a cough that won’t quit, consult a primary care doctor or gastroenterologist for evaluation.
For those struggling with sleep quality due to environmental factors, such as heat, sleep experts also recommend practical strategies to improve rest. For example, some specialists share their own approaches for coping with hot nights when air conditioning isn’t available, as described in this feature on how sleep professionals handle extreme heat.
According to the Centers for Disease Control and Prevention, about 20% of American adults experience symptoms of GERD at least once a week. The prevalence rises with age and is higher among women. Untreated reflux can lead to complications like esophagitis or even precancerous changes in the esophagus. Simple lifestyle changes—like adjusting sleep position—are often recommended as a first step before medication or more invasive treatments are considered.
GERD is a chronic condition that can significantly impact quality of life. While medications such as proton pump inhibitors and H2 blockers are commonly prescribed, non-drug interventions remain a cornerstone of management. Sleep hygiene, dietary adjustments, and weight management all play a role. For many, a combination of these strategies provides the best relief and helps prevent long-term complications.
